ASPHALTENE DEPOSITION CONTROL

Abstract

The use of a three-way combination of additives comprising (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent; (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, to inhibit asphaltene precipitation from crude oil.

Claims

1. A method for inhibiting precipitation of asphaltene(s) from a crude oil having an asphaltene content, the method comprising: (A) providing a crude oil in a major amount, the crude oil having an asphaltene content; and (B) introducing into the crude oil a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), in an effective minor amount, to inhibit precipitation of asphaltene(s) from the crude oil, wherein the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) comprises or is made by admixing: (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine.

2. A three-way combination of additives (B)(i), (B)(ii) and (B)(iii) comprising or made by admixing: (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine.

3. A method for improving the transportation of a crude oil, the method comprising the steps of: (i) introducing a minor amount of the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) of claim 2, into (A) a major amount of a crude oil having an asphaltene content; and (ii) transporting said crude oil.

4. A method of preparing a crude oil composition comprising introducing a minor amount of the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) of claim 2 into a major amount of a crude oil having an asphaltene content.

5. A crude oil composition comprising or made by admixing: (A) a crude oil having an asphaltene content in a major amount; and (B) the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) of claim 2 in a minor amount.

6. An additive composition suitable for introduction into to a crude oil having an asphaltene content to inhibit precipitation of asphaltene(s) from the crude oil, the additive composition comprising or made by admixing: a hydrocarbon diluent fluid; and the three-way combination of each of said additive(s) (B)(i), (B)(ii) and (B)(iii) of claim 2.

7. A method to inhibit deposition of asphaltene(s) from the crude oil comprising combining the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) of claim 2, in an effective minor amount with a crude oil having an asphaltene content and inhibiting the deposition of asphaltene(s) from the crude oil.

8. A method to inhibit deposition of asphaltene(s) from the crude oil comprising combining the additive composition of claim 6 with a crude oil having an asphaltene content and inhibiting the deposition of asphaltene(s) from the crude oil.

9. The method of claim 1, wherein the ratio of the total combined individual amounts of additives (B)(i) and (B)(ii) on a mass % active ingredient basis to total the amount of additive(s) (B)(iii) on a mass % active ingredient basis in the crude oil, based on the total amount of crude oil, is in the range of 8:1 to 1:1.

8. The method of claim 1, wherein the treat rate of the three-way additive combination of (B)(i), (B)(ii) and (B)(iii) is greater than or equal to 75 ppm by mass based on the total mass of crude oil.

9. The method of claim 1, wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent (B)(i) comprises an alkaline earth metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent.

10. The method of claim 9, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent comprises a calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent.

11. The method of claim 10, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent has a total base number (TBN) at 100% active mass of less than or equal to 100 mg KOH/g as measured by ASTM D2896.

12. The method of claim 1, wherein said poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii) comprises a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid.

13. The method of claim 1, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises an alkylene polyamine having from 2 to 20 total number of carbon atoms and from 2 to 12 amine groups.

14. The method of claim 1, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises a polyethylene polyamine.

15. The method of claim 1, wherein the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) used to obtain said aliphatic hydrocarbyl acid amide (B)(iii) comprises a (C.sub.9 to C.sub.29)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.9 to C.sub.29)alkenyl-substituted monocarboxylic acid or derivative thereof.

16. The method of claim 1, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride(s), a poly(C.sub.2 to C.sub.6)alkenyl-substituted di-acid(s), or a poly(C.sub.2 to C.sub.6)alkenyl-substituted diols(s).

17. The method of claim 1, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a (C.sub.10 to C.sub.30)alkyl-substituted anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted anhydride(s).

18. The method of claim 1, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8 total nitrogen atoms.

19. The method of claim 17, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting said polyethylene polyamine (B)(iii)(a) and (B)(iii)(b) isostearic acid or derivative thereof.

20. The method of claim 1, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid imide which is obtainable by reacting (B)(iii)(c) a (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) or (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s) and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8 total nitrogen atoms.

21. The method of claim 1, wherein the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) is introduced into said crude oil during an up-stream or mid-stream crude oil transportation, storage or processing operation.

22. The method of claim 21, wherein said crude oil is in the form of a crude oil stream.

23. The method of claim 1, wherein said crude oil has been recovered by a secondary or enhanced crude oil recovery process.

24. The method of claim 11, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent has a total base number (TBN) at 100% active mass of less than or equal to 75 mg KOH/g as measured by ASTM D2896.

25. The method of claim 1, wherein the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) used to obtain said aliphatic hydrocarbyl acid amide (B)(iii) comprises a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof.

26. The method of claim 16, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a polyisobutenyl succinic anhydride(s) or polyisobutenyl succinic acid(s).

27. The method of claim 17, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s).

28. The method of claim 18, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 6 total nitrogen atoms.

29. The method of claim 28, wherein said polyethylene polyamine (B)(iii)(a) comprises tetraethylene pentaamine.

30. The method of claim 20, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid imide which is obtainable by reacting (B)(iii)(c) a (C.sub.18)alkyl-substituted succinic anhydride(s) and/or (C.sub.18)alkenyl-substituted succinic anhydride(s), and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8 total nitrogen atoms.

31. Use of a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), as defined in claim 2, in an effective minor amount in a crude oil having an asphaltene content to inhibit deposition of asphaltene(s) from the crude oil.

32. The use of claim 31, wherein the combination of additives (B)(i), (B)(ii) and (B)(iii) are in the form of a crude oil additive composition.

33. A crude oil composition comprising or made by admixing crude oil containing asphaltenes and the three-way combination of each of additive(s) (B)(i), (B)(ii) and (B)(iii) of claim 2.

34. The composition of claim 33, wherein the ratio of the total combined individual amounts of additives (B)(i) and (B)(ii) on a mass % active ingredient basis to total the amount of additive(s) (B)(iii) on a mass % active ingredient basis in the crude oil, based on the total amount of crude oil, is in the range of 8:1 to 1:1.

35. The composition of claim 33, wherein the three-way additive combination of (B)(i), (B)(ii) and (B)(iii) is present at greater than or equal to 75 ppm by mass based on the total mass of crude oil.

36. The composition of claim 2, wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent (B)(i) comprises an alkaline earth metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent.

37. The composition of claim 2, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent comprises a calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent.

38. The composition of claim 36, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent has a total base number (TBN) at 100% active mass of less than or equal to 100 mg KOH/g as measured by ASTM D2896.

39. The composition of paragraph claim 2, wherein said poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii) comprises a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid.

40. The composition of claim 2, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises an alkylene polyamine having from 2 to 20 total number of carbon atoms and from 2 to 12 amine groups.

41. The composition of claim 2, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises a polyethylene polyamine.

42. The composition of claim 2, wherein the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) used to obtain said aliphatic hydrocarbyl acid amide (B)(iii) comprises a (C.sub.9 to C.sub.29)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.9 to C.sub.29)alkenyl-substituted monocarboxylic acid or derivative thereof.

43. The composition of claim 2, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride(s), a poly(C.sub.2 to C.sub.6)alkenyl-substituted di-acid(s), or a poly(C.sub.2 to C.sub.6)alkenyl-substituted diols(s).

44. The composition of claim 2, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a (C.sub.10 to C.sub.30)alkyl-substituted anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted anhydride(s).

45. The composition of claim 2, A13 or A14, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8 total nitrogen atoms, as defined and identified herein.

46. The composition of claim 2, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting said polyethylene polyamine (B)(iii)(a), preferably tetraethylene pentaamine, and (B)(iii)(b) isostearic acid or derivative thereof.

47. The composition of claim 2, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid imide which is obtainable by reacting (B)(iii)(c) a (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) or (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s), preferably a (C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.18)alkenyl-substituted succinic anhydride(s), and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8 total nitrogen atoms.

48. A crude oil composition comprising or made by admixing crude oil containing asphaltenes and (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; optionally, (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and, optionally, (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid, or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

Additive B(i)Metal Hydroxybenzoate Detergent

[0196] Additive B(i) is a metal hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said detergent has a valency of +1 or +2 and wherein said metal hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896. Suitably, the metal hydrocarbyl-substituted hydroxybenzoate detergent is oil-soluble or oil-dispersible.

[0197] A metal detergent is an additive based on so-called metal soaps, that is metal salts of acidic organic compounds, sometimes referred to as surfactants, which generally comprise a polar head with a long hydrophobic tail. The surfactant of additive (B)(i) is a hydrocarbyl-substituted hydroxybenzoic acid. The metal of additive (B)(i) is a metal having a valency of +1 or +2.

[0198] Preferably, the metal hydrocarbyl-substituted hydroxybenzoate detergent is a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, more preferably a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent.

[0199] The one or more metal C.sub.10 to C.sub.40 hydrocarbyl substituted hydroxybenzoates typically comprise one or more compounds of Formula I:

##STR00001## [0200] wherein R.sup.1 represents a (C.sub.10 to C.sub.40)hydrocarbyl group that is predominantly aliphatic in nature having 10 to 40 carbon atoms, M is a metal, n is an integer of 1 or 2 depending on the valence of the metal, and m is an integer of 1 to 3.

[0201] The more preferred one or more metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylates typically comprise one or more compounds of Formula II:

##STR00002## [0202] wherein R.sup.1, M, n and m are as defined for a compound of formula I.

[0203] For the avoidance of doubt, the preferred features of the C.sub.10 to C.sub.40 hydrocarbyl substituted hydroxybenzoates also represent preferred features of the C.sub.10 to C.sub.40 hydrocarbyl substituted salicylates and vice versa.

[0204] Preferably, the metal of said metal hydrocarbyl-substituted hydroxybenzoate detergent which has a valency of +1 or +2 (i.e., M in a compound of formula I and formula II) is selected from: an alkali metal, such as lithium, sodium or potassium; an alkaline earth metal, such as magnesium, calcium barium or strontium; or, a metal such as zinc. More preferably, the metal of said metal hydrocarbyl-substituted hydroxybenzoate detergent is an alkaline earth metal, such as magnesium or calcium, especially calcium. Accordingly a highly preferred metal hydrocarbyl-substituted hydroxybenzoate detergent comprises a calcium hydrocarbyl-substituted salicylate detergent, especially a calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent, i.e., a compound of formula II where M represents calcium.

[0205] Preferably, the hydrocarbyl group of said metal hydrocarbyl-substituted hydroxybenzoate detergent consists solely of carbon and hydrogen atoms. The hydrocarbyl group is predominantly aliphatic in nature and it is preferably purely aliphatic. Purely aliphatic hydrocarbyl groups include linear or branched aliphatic groups, for example linear or branched alkyl or alkenyl groups. Most preferably, the hydrocarbyl group represents a linear (i.e., straight chain) or branched alkyl group.

[0206] Examples of C.sub.10 to C.sub.40 alkyl groups (which may be linear or branched) include decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneicosyl, dococyl, tricocyl, tetracocyl, pentacocyl, hexacocyl, heptacocyl, octacocyl, nonacocyl, and triacontyl. Examples of C.sub.10 to C.sub.40 alkenyl groups (which may be linear or branched, the position of the double bond being arbitrary) include decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicosenyl, heneicosenyl, dococenyl, tricocenyl, tetracocenyl, pentacocenyl, hexacocenyl, heptacocenyl, octacocenyl, nonacocenyl, and triacontenyl.

[0207] Preferably, the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent (which includes the preferred (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergents), as defined herein, comprises a metal (C.sub.10 to C.sub.30)hydrocarbyl-substituted hydroxybenzoate detergent, more preferably a metal (C.sub.10 to C.sub.20)hydrocarbyl-substituted hydroxybenzoate detergent, even more preferably a metal (C.sub.16 to C.sub.18)hydrocarbyl-substituted hydroxybenzoate detergent. As stated herein, the preferred (C.sub.10 to C.sub.40)hydrocarbyl substituent groups comprise (C.sub.10 to C.sub.40)alkyl substituent groups, as defined herein, which alkyl groups may be linear or branched.

[0208] The basicity of a detergent is typically expressed as a total base number (TBN). A total base number is the amount of acid needed to neutralise all the basicity of the material. The TBN may be measured using ASTM standard D2896.

[0209] An essential feature of the metal hydrocarbyl-substituted hydroxybenzoate detergent is that it has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896. Preferably, the metal hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 125, more preferably less than or equal to 100, more preferably less than or equal to 75, even more preferably less than or equal to 70, mg KOH/g as measured by ASTM D2896.

[0210] Suitably, the metal hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of greater than or equal to 20, preferably greater than or equal to 30, more preferably greater than or equal to 40, more preferably greater than or equal to 50, even more preferably greater than or equal to 60, mg KOH/g as measured by ASTM D2896.

[0211] Suitably, the metal hydrocarbyl-substituted hydroxybenzoate detergent may consist essentially of a single metal hydrocarbyl-substituted hydroxybenzoate detergent. Alternatively, the metal hydrocarbyl-substituted hydroxybenzoate detergent may comprise a mixture of one or more different metal hydrocarbyl-substituted hydroxybenzoate detergents. Suitably, it will be appreciated that when a mixture of one or more different metal hydrocarbyl-substituted hydroxybenzoate detergents is used, then the resulting total base number of the mixture of detergents is as defined and identified herein.

[0212] Metal detergents may be overbased, low-based or neutral. The term overbased is generally used to describe metal detergents in which the ratio of the number of equivalents of the metal moiety to the number of equivalents of the acid moiety is substantially greater than one. Suitably, the term neutral is generally used to describe metal detergents in which the ratio of the number of equivalents of the metal moiety to the number of equivalents of the acid moiety is essentially equal to one (e.g., up to 1.2, such as up to 1.1). The term low based is typically used to describe metal detergents in which the equivalent ratio of metal moiety to acid moiety is greater than 1 and up to about 2. Preferably, the metal hydrocarbyl-substituted hydroxybenzoate detergent (i.e., metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylates) is low-based, more preferably essentially neutral.

[0213] Hydroxybenzoic acids, particularly salicylic acids, are typically prepared by the carboxylation, by the Kolbe-Schmitt process, of phenoxides, and in that case, will generally be obtained (normally in a diluent) in admixture with uncarboxylated phenol. Salicylic acids may be non-sulphurized or sulphurized, and may be chemically modified and/or contain additional substituents. Processes for sulphurizing a hydrocarbyl-substituted salicylic acid are well known to those skilled in the art, and are described, for example, in US 2007/0027057.

[0214] Suitably, the one or more C.sub.10 to C.sub.40 hydrocarbyl substituted hydroxybenzoic acids may be formed by the carboxylation of the corresponding one or more C.sub.10 to C.sub.40 hydrocarbyl substituted phenols. Typically, this process can be accomplished by treating the one or more C.sub.10 to C.sub.40 hydrocarbyl substituted phenols with a base to form the corresponding phenoxides, and then treating the phenoxides with carbon dioxide at an elevated pressure and temperature.

[0215] In general, neutral metal hydrocarbyl-substituted salicylates can be prepared by neutralisation of hydrocarbyl-substituted salicylic acid with an equivalent quantity of metallic base. However, a preferred method of preparing a neutral calcium salt of salicylic acid is through double decomposition of methanolic solutions of calcium chloride and sodium hydroxide in the presence of hydrocarbyl-substituted salicylic acid, followed by removal of solids and process solvents.

[0216] Suitably, the metal hydrocarbyl-substituted hydroxybenzoate detergent, as defined and identified herein, particularly the highly preferred calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent, is present in an amount of (i.e., introduced into the crude oil in an amount of) greater than or equal to 5, preferably greater than or equal to 10, more preferably greater than or equal to 75, more preferably greater than or equal to 100, ppm by mass based on the total mass of crude oil.

[0217] Suitably, the metal hydrocarbyl-substituted hydroxybenzoate detergent, particularly the highly preferred calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent, is present in an amount of (i.e., introduced into the crude oil in an amount of) less than or equal to 10,000, preferably less than or equal to 5000, more preferably less than or equal to 1000, more preferably less than or equal to 750, more preferably less than or equal to 500, ppm by mass based on the total mass of crude oil.

[0218] Suitable, metal hydrocarbyl-substituted hydroxybenzoate detergent for use in the invention are available from Infineum UK Ltd.

Additive B(ii)Alkenyl-Substituted Anhydride or Acid

[0219] Additive B(ii) is a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid, as defined herein. Suitably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid is oil-soluble or oil-dispersible.

[0220] Suitably, each of the poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride and poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii), as defined herein, include a poly(C.sub.2 to C.sub.6)alkenyl substituent group, which substituent group may be formed by homo-polymerisation or co-polymerisation of one or more (C.sub.2 to C.sub.6)alkene(s).

[0221] Suitable polymers employed in the formation of the anhydride(s) and acid(s) of (B)(ii) to generate the poly(C.sub.2 to C.sub.6)alkenyl moieties include homopolymers, interpolymers or lower molecular weight hydrocarbons. One family of such polymers comprise polymers of ethylene and/or at least one C.sub.3 to C.sub.6 alpha-olefin having the formula H.sub.2C?CHR.sup.1 wherein R.sup.1 is straight or branched-chain alkyl radical comprising 1 to 4 carbon atoms and wherein the polymer contains carbon-to-carbon unsaturation, preferably a high degree of terminal ethenylidene unsaturation. Preferably, such polymers comprise interpolymers of ethylene and at least one alpha-olefin of the above formula, wherein R.sup.1 is alkyl of from 1 to 4, more preferably from 1 to 2, carbon atoms. Therefore, useful alpha-olefin monomers and comonomers include, for example, propylene, but-1-ene-1, hex-1-ene, and mixtures thereof (e.g., mixtures of propylene and but-1-ene-1). Exemplary of such polymers are propylene homopolymers, but-1-ene homopolymers, ethylene-propylene copolymers, ethylene-but-1-ene copolymers, and propylene-butene copolymers, wherein the polymer contains at least some terminal and/or internal unsaturation. Preferred copolymers are unsaturated copolymers of ethylene and propylene and copolymers of ethylene and but-1-ene. It is preferred that the polymers comprise only alpha-olefin homopolymers, interpolymers of alpha-olefin comonomers and interpolymers of ethylene and alpha-olefin comonomers. The molar ethylene content of the polymers employed is preferably in the range of 0 to 80, more preferably 0 to 60%. When propylene and/or butene-1 are employed as comonomer(s) with ethylene, the ethylene content of such copolymers is most preferably between 15 and 50%, although higher or lower ethylene contents may be present.

[0222] These polymers may be prepared by polymerizing an alpha-olefin monomer, or mixtures of alpha-olefin monomers, or mixtures comprising ethylene and at least one C.sub.3 to C.sub.6 alpha-olefin monomer, in the presence of a catalyst system comprising at least one metallocene (e.g., a cyclopentadienyl-transition metal compound) and an alumoxane compound. Using this process, a polymer in which 95% or more of the polymer chains possess terminal ethenylidene-type unsaturation can be provided. The percentage of polymer chains exhibiting terminal ethenylidene unsaturation may be determined by FTIR spectroscopic analysis, titration, or C.sub.13 NMR. Interpolymers of this latter type may be characterized by the formula POLY-C(R.sup.1)?CH.sub.2 wherein R.sup.1 is C.sub.1 to C.sub.4, preferably C.sub.1 to C.sub.2, alkyl, (e.g., methyl or ethyl) and wherein POLY represents the polymer chain. The chain length of the R.sup.1 alkyl group will vary depending on the comonomer(s) selected for use in the polymerization. A minor amount of the polymer chains can contain terminal ethenyl, i.e., vinyl, unsaturation, i.e., POLY-CH?CH.sub.2, and a portion of the polymers can contain internal mono-unsaturation, e.g., POLYCH?CH(R.sup.1), wherein R.sup.1 is as defined above. These terminally unsaturated interpolymers May be prepared by known metallocene chemistry and may also be prepared as described in U.S. Pat. Nos. 5,498,809; 5,663,130; 5,705,577; 5,814,715; 6,022,929; and 6,030,930.

[0223] Another useful class of polymers is that of polymers prepared by cationic polymerization of isobutene. Common polymers from this class include polyisobutenes, otherwise known as polyisobutylenes, obtained by polymerization of a C.sub.4 refinery stream having a butene content of 35 to 75 mass %, and an isobutene content of 30 to 60 mass %, in the presence of a Lewis acid catalyst, such as aluminum trichloride or boron trifluoride. A preferred source of monomer for making poly-n-butenes is a petroleum feedstream such as Raffinate II. These feedstocks are disclosed in the art such as in U.S. Pat. No. 4,952,739. Polyisobutene is a most preferred substituent group of said anhydride(s) or acid(s) (B)(ii) because it is readily available by cationic polymerization from butene streams (e.g., using AlCl.sub.3 or BF.sub.3 catalysts). Such polyisobutenes generally contain residual unsaturation in amounts of one ethylenic double bond per polymer chain, positioned along the chain. A preferred embodiment utilizes polyisobutene prepared from a pure isobutene stream or a Raffinate I stream to prepare reactive isobutene polymers with terminal vinylidene olefins. Preferably, these polymers, referred to as highly reactive polyisobutylene (HR-PIB), have a terminal vinylidene content of at least 65, e.g., 70, more preferably at least 80, most preferably at least 85%. The preparation of such polymers is described, for example, in U.S. Pat. No. 4,152,499. HRPIB is known and HRPIB is commercially available under the tradenames Glissopal? (from BASF) and Ultravis? (from BP-Amoco).

[0224] Methods for making polyisobutene are known. Polyisobutene can be functionalized by halogenation (e.g., chlorination), the thermal ene reaction, or by free radical grafting using a catalyst (e.g., peroxide), as described below.

[0225] The hydrocarbon or polymer backbone may be functionalized with carboxylic anhydride-producing moieties selectively at sites of carbon-to-carbon unsaturation on the polymer or hydrocarbon chains, or randomly along chains using any of the three processes mentioned above or combinations thereof, in any sequence.

[0226] Processes for reacting polymeric hydrocarbons with unsaturated carboxylic acids, anhydrides and the preparation of derivatives from such compounds are disclosed in U.S. Pat. Nos. 3,087,936; 3,172,892; 3,215,707; 3,231,587; 3,272,746; 3,275,554; 3,381,022; 3,442,808; 3,565,804; 3,912,764; 4,110,349; 4,234,435; 5,777,025; 5,891,953; as well as EP 0 382 450 B1; CA-1,335,895 and GB-A-1,440,219. The polymer or hydrocarbon may be functionalized, with carboxylic acid anhydride moieties by reacting the polymer or hydrocarbon under conditions that result in the addition of functional moieties or agents, i.e., acid anhydride, onto the polymer or hydrocarbon chains primarily at sites of carbon-to-carbon unsaturation (also referred to as ethylenic or olefinic unsaturation) using the halogen assisted functionalization (e.g., chlorination) process or the thermal ene reaction.

[0227] Selective functionalization can be accomplished by halogenating, e.g., chlorinating or brominating, the unsaturated ?-olefin polymer to 1 to 8, preferably 3 to 7, mass % chlorine, or bromine, based on the weight of polymer or hydrocarbon, by passing the chlorine or bromine through the polymer at a temperature of 60 to 250, preferably 110 to 160, e.g., 120 to 140? C., for 0.5 to 10, preferably 1 to 7, hours. The halogenated polymer or hydrocarbon (hereinafter backbone) is then reacted with sufficient monounsaturated reactant capable of adding the required number of functional moieties to the backbone, e.g., monounsaturated carboxylic reactant, at 100 to 250, usually 180 to 235? C., for 0.5 to 10, e.g., 3 to 8, hours, such that the product obtained will contain the desired number of moles of the monounsaturated carboxylic reactant per mole of the halogenated backbones. Alternatively, the backbone and the monounsaturated carboxylic reactant are mixed and heated while adding chlorine to the hot material.

[0228] While chlorination normally helps increase the reactivity of starting olefin polymers with monounsaturated functionalizing reactant, it is not necessary with some of the polymers or hydrocarbons contemplated for use in the present invention, particularly those preferred polymers or hydrocarbons which possess a high terminal bond content and reactivity. Preferably, therefore, the backbone and the monounsaturated functionality reactant, (carboxylic reactant), are contacted at elevated temperature to cause an initial thermal ene reaction to take place. Ene reactions are known.

[0229] The hydrocarbon or polymer backbone can be functionalized by random attachment of functional moieties along the polymer chains by a variety of methods. For example, the polymer, in solution or in solid form, may be grafted with the monounsaturated carboxylic reactant, as described above, in the presence of a free-radical initiator. When performed in solution, the grafting takes place at an elevated temperature in the range of 100 to 260, preferably 120 to 240? C. Preferably, free-radical initiated grafting would be accomplished in a mineral lubricating oil solution containing, e.g., 1 to 50, preferably 5 to 30, mass % polymer based on the initial total oil solution.

[0230] The free-radical initiators that may be used are peroxides, hydroperoxides, and azo compounds, preferably those that have a boiling point greater than 100? C. and decompose thermally within the grafting temperature range to provide free-radicals. Representative of these free-radical initiators are azobutyronitrile, 2,5-dimethylhex-3-ene-2, 5-bis-tertiary-butyl peroxide and dicumene peroxide. The initiator, when used, is typically in an amount of between 0.005 and 1% by weight based on the weight of the reaction mixture solution. Typically, the aforesaid monounsaturated carboxylic reactant material and free-radical initiator are used in a weight ratio range of from 1.0:1 to 30:1, preferably 3:1 to 6:1. The grafting is preferably carried out in an inert atmosphere, such as under nitrogen blanketing. The resulting grafted polymer is characterized by having carboxylic acid (or derivative) moieties randomly attached along the polymer chains, it being understood that some of the polymer chains remain ungrafted. The free radical grafting described above can be used for the other polymers and hydrocarbons used in the present invention.

[0231] The preferred monounsaturated reactants that are used to functionalize the backbone comprise mono- and dicarboxylic acid material, i.e., acid, or acid derivative material, including (i) monounsaturated C.sub.4 to C.sub.10 dicarboxylic acid wherein (a) the carboxyl groups are vicinyl, (i.e., located on adjacent carbon atoms) and (b) at least one, preferably both, of the adjacent carbon atoms are part of the mono unsaturation; (ii) derivatives of (i) such as anhydrides or C.sub.1 to C.sub.5 alcohol derived mono- or diesters of (i); (iii) monounsaturated C.sub.3 to C.sub.10 monocarboxylic acid wherein the carbon-carbon double bond is conjugated with the carboxy group, i.e., of the structure C?CCO; and (iv) derivatives of (iii) such as C.sub.1 to C.sub.5 alcohol derived mono- or diesters of (iii). Mixtures of monounsaturated carboxylic materials (i)-(iv) also may be used. Upon reaction with the backbone, the monounsaturation of the monounsaturated carboxylic reactant becomes saturated. Thus, for example, maleic anhydride becomes backbone-substituted succinic anhydride, and acrylic acid becomes backbone-substituted propionic acid. Exemplary of such monounsaturated carboxylic reactants are fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, chloromaleic anhydride, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and lower alkyl (e.g., C.sub.1 to C.sub.4 alkyl) acid esters of the foregoing, e.g., methyl maleate, ethyl fumarate, and methyl fumarate.

[0232] To provide the required functionality, the monounsaturated carboxylic reactant, preferably maleic anhydride, typically will be used in an amount ranging from equimolar amount to 100, preferably 5 to 50, mass % excess, based on the moles of polymer or hydrocarbon. Unreacted excess monounsaturated carboxylic reactant can be removed from the final dispersant product by, for example, stripping, usually under vacuum, if required.

[0233] Preferably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride which (B)(ii) may represent comprises poly(C.sub.2 to C.sub.6)alkenyl-substituted succinic anhydride, such as poly(ethylenyl) succinic anhydride(s), poly(propylenyl) succinic anhydride(s), poly(butenyl) succinic anhydride(s), poly(isobutenyl) succinic anhydride(s) or combinations thereof.

[0234] Preferably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted acid which (B)(ii) may represent comprises a poly(C.sub.2 to C.sub.6)alkenyl-substituted di-acid, especially a poly(C.sub.2 to C.sub.6)alkenyl-substituted succinic acid, such as poly(ethylenyl) succinic acid(s), poly(propylenyl) succinic acid(s), poly(butenyl) succinic acid(s), poly(isobutenyl) succinic acid(s) or combinations thereof.

[0235] A most preferred poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride which (B)(ii) may represent comprises a polyisobutenyl-substituted succinic anhydride (PIBSA).

[0236] A most preferred poly(C.sub.2 to C.sub.6)alkenyl-substituted acid which (B)(ii) may represent comprises a polyisobutenyl-substituted succinic acid.

[0237] Preferably, the number average molecular weight (Mn) of the poly(C.sub.2 to C.sub.6)alkenyl substituent group of said poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii), as defined or identified herein, particularly the number average molecular weight (Mn) of the polyisobutenyl substituent group of the preferred polyisobutenyl-substituted succinic anhydride or polyisobutenyl-substituted succinic acid, is greater than or equal to 100, preferably greater than or equal to 150, preferably greater than or equal to 200, preferably greater than or equal to 250, preferably greater than or equal to 300, preferably greater than or equal to 350, preferably greater than or equal to 400, daltons.

[0238] Preferably, the number average molecular weight (Mn) of the poly(C.sub.2 to C.sub.6)alkenyl substituent group of said poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii), as defined or identified herein, particularly the number average molecular weight (Mn) of the polyisobutenyl substituent group of the preferred polyisobutenyl-substituted succinic anhydride or polyisobutenyl-substituted succinic acid, is less than or equal to 7000, preferably less than or equal to 5000, preferably less than or equal to 4000, preferably less than or equal to 3000, daltons.

[0239] Suitably, the ratio of the weight average molecular weight (Mw) to number average molecular weight (Mn), i.e., Mw/Mn, of the poly(C.sub.2 to C.sub.6)alkenyl substituent group(s) of said poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) or poly(C.sub.2 to C.sub.6)alkenyl-substituted 25 acid(s), as defined herein, is from 1.5 to 4.0.

[0240] Suitably, the average succination ratio of the one or more poly(C.sub.2 to C.sub.6)alkenyl succinic anhydride(s), as defined herein, especially said one or more polyisobutenyl succinic anhydride(s), is greater than or equal to 1.35, more preferably greater than or equal to 1.40, even more preferably greater than or equal to 1.45, even more preferably greater than or equal to 1.50, even more preferably greater than or equal to 1.55. Preferably, the average succination ratio of the one or more poly(C.sub.2 to C.sub.6)alkenyl succinic anhydride(s), as defined herein, especially said one or more polyisobutenyl succinic anhydride(s), is less than or equal to 4.00, more preferably less than or equal to 3.50, even more preferably less than or equal to 3.20, even more preferably less than or equal to 3.00, even more preferably less than or equal to 2.75, even more preferably less than or equal to 2.50. A highly preferred average succination ratio of the one or more poly(C.sub.2 to C.sub.6)alkenyl succinic anhydride(s), especially said one or more polyisobutenyl succinic anhydride(s), is from 1.35 to 3.50, especially from 1.40 to 3.00.

[0241] A highly preferred additive (B)(ii) comprises polyisobutenyl succinic anhydride or polyisobutenyl succinic acid having a Mn of from 400 to 4000 daltons, particularly polyisobutenyl succinic anhydride having a Mn of from 400 to 4000 daltons, especially 400 to 3000 daltons. Polyisobutenyl succinic anhydride(s) or polyisobutenyl succinic acid(s) having a Mn of from 400 to 1250 daltons are particularly preferred.

[0242] Suitably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii), as defined or identified herein, particularly the highly preferred polyisobutenyl-substituted succinic anhydride or polyisobutenyl-substituted succinic acid, is present (i.e., introduced into the oil) in an amount of greater than or equal to 5, preferably greater than or equal to 10, more preferably greater than or equal to 15, more preferably greater than or equal to 20, more preferably greater than or equal to 25, ppm by mass based on the total mass of crude oil.

[0243] Suitably, in each aspect of the invention, the poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii), as defined or identified herein, particularly the highly preferred polyisobutenyl-substituted succinic anhydride or polyisobutenyl-substituted succinic acid, is present (i.e., introduced into the oil) in an amount of less than or equal to 5000, preferably less than or equal to 3000, more preferably less than or equal to 1000, more preferably less than or equal to 750, more preferably less than or equal to 500, more preferably less than or equal to 250, ppm by mass based on the total mass of crude oil.

Additive B(iii)Hydrocarbyl-Substituted Amide or Imide

[0244] Additive (B)(iii) is an aliphatic hydrocarbyl acid amide or an aliphatic hydrocarbyl acid imide, or a combination thereof. The aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtainable by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, aliphatic hydrocarbyl-substituted di-acid, or an aliphatic hydrocarbyl-substituted diol, wherein the aliphatic alkylene polyamine has at least two carbon atoms and at least two amine groups wherein at least one of amine groups is a primary amine group.

[0245] It will be appreciated that additive (B)(iii) is an ashless organic additive. Suitably, additive (B)(iii) is oil-soluble or oil-dispersible.

[0246] Suitably, (B)(iii) the aliphatic hydrocarbyl acid amide or aliphatic hydrocarbyl acid imide, as defined or identified herein, is present in an amount of greater than or equal to 5, preferably greater than or equal to 10, more preferably greater than or equal to 15, more preferably greater than or equal to 20, more preferably greater than or equal to 25, ppm by mass based on the total mass of crude oil.

[0247] Suitably, (B)(iii) the aliphatic hydrocarbyl acid amide or aliphatic hydrocarbyl acid imide, as defined or identified herein, is present in an amount of less than or equal to 5000, preferably less than or equal to 3000, more preferably less than or equal to 1000, more preferably less than or equal to 750, more preferably less than or equal to 500, more preferably less than or equal to 250, ppm by mass based on the total mass of crude oil.

(B)(iii)(a) Aliphatic Alkylene Polyamine

[0248] The aliphatic alkylene polyamine (B)(iii)(a) which may be reacted with either (B)(iii)(b) said aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof, as defined herein, or with (B)(iii)(c) said aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, each as further defined herein, has at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group.

[0249] Suitably, the aliphatic alkylene polyamine may be an alkyl polyamine, as defined and identified herein, or a polyalkylene polyamine, as defined and identified herein, or a combination thereof.

[0250] Suitably, the alkyl polyamine has a primary amine group bonded to a first carbon atom of an alkanediyl radical and at least a second amine group bonded to a different carbon atom of said alkanediyl radical. Accordingly, the alkanediyl radical has at least two carbon atoms. Suitable alkyl polyamine(s) include alkane(s) which are terminated with at least one primary amine group and further substituted and/or terminated with at least one further amine group. Accordingly, suitable alkyl polyamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,2-diaminomethyl-3-aminopropane, especially 1,2-diaminomethyl-3-aminopropane.

[0251] Suitably, the polyalkylene polyamine has two or more alkanediyl radical repeating units and at least 3 amine groups. The said first amine group is bonded to the second amine group by a first alkanediyl radical, and the second amine group is bonded to the third amine group by a second alkanediyl radical. Accordingly, the polyalkylene polyamine includes at least one primary amine group and at least one secondary amine group.

[0252] Preferably, the aliphatic alkylene polyamine comprises a polyalkylene polyamine, as defined and identified herein.

[0253] The aliphatic alkylene polyamine, as defined and identified herein, contains at least 2, and typically from 2 to 60, preferably 2 to 40, more preferably 4 to 20, even more preferably 4 to 20, even more preferably 4 to 12, especially 4 to 10 total carbon atoms.

[0254] The aliphatic alkylene polyamine, as defined and identified herein, contains at least two amine groups, and typically from 2 to 12, preferably 2 to 10, more preferably 3 to 10, even more preferably 3 to 8, even more preferably 3 to 6, total amine groups. Highly preferred aliphatic alkylene polyamines include 3, 4, 5, 6, 7, or 8 total amine groups, especially 3, 4, 5, or 6 total nitrogen atoms.

[0255] Suitably, each nitrogen atom of the aliphatic alkylene polyamine may independently represent a primary, secondary or tertiary amine group.

[0256] In an embodiment, the aliphatic alkylene polyamine includes at least two primary amine groups (i.e., at least 2 nitrogen atoms represent a primary amine group). It is preferred that the aliphatic alkylene polyamine has a total number of two primary amine groups.

[0257] In an embodiment, the aliphatic alkylene polyamine includes at least one secondary amine groups (i.e., at least 1 nitrogen atom represents a secondary amine group), and typically from 1 to 10, preferably 1 to 8, more preferably 1 to 7, even more preferably 1 to 6, even more preferably 1 to 4, secondary amine group(s).

[0258] In an embodiment, albeit less preferred, the aliphatic alkylene polyamine includes at least one tertiary amine group, preferably a single tertiary amine group (i.e., at least 1 nitrogen atom represents a tertiary amine group).

[0259] Suitably, the aliphatic alkylene polyamine includes a primary amine group and at least one further primary amine and/or secondary amine group.

[0260] Preferably, the aliphatic alkylene polyamine, includes at least two primary amine groups, preferably only two primary amine groups with any further amine group(s) being secondary amine group(s). Accordingly, preferred aliphatic alkylene polyamine(s) include those which include a combination of primary amine group(s) and secondary amine group(s) only.

[0261] Accordingly, preferred aliphatic alkylene polyamines, including the more preferred polyalkylene polyamine(s), include at least one primary amine group, preferably two primary amine groups, and at least one secondary amine group, typically from 1 to 10, preferably 1 to 8, more preferably 1 to 7, even more preferably 1 to 6, even more preferably 1 to 4, secondary amine group(s). Highly preferred aliphatic alkylene polyamine(s), including the preferred polyalkylene polyamine(s), comprise of only primary and secondary amine groups, have two primary amine groups and at least one secondary amine group, typically from 1 to 10, preferably 1 to 8, more preferably 1 to 7, even more preferably 1 to 6, secondary amine group(s).

[0262] The following aliphatic alkylene polyamine description is subject to the above constraints regarding carbon and nitrogen atom content, and the variable groups for the following formulae are to be selected in conformance with such constraints. Additionally, the following aliphatic alkylene polyamine description is also limited to amines which must have at least one nitrogen atom present in the form of a primary amine group and at least one of the remaining nitrogen atoms present in the form of a primary or secondary amine group.

[0263] Suitably, the aliphatic alkylene polyamine may comprise an aliphatic (C.sub.2 to C.sub.60), preferably (C.sub.2 to C.sub.40), more preferably (C.sub.2 to C.sub.20), even more preferably (C.sub.4 to C.sub.20), even more preferably (C.sub.4 to C.sub.12), especially (C.sub.4 to C.sub.10), alkylene polyamine. Suitably, the alkylene group of said aliphatic alkylene polyamine comprises an aliphatic acyclic alkylene group. Suitably, the alkylene group of said aliphatic alkylene polyamine may be straight or branched chain, preferably a straight chain. Preferably, the aliphatic alkylene group is unsubstituted. It will be appreciated that the alkylene group of said aliphatic alkylene polyamine is terminated with at least one primary amine group and/or interrupted by one or more nitrogen atoms to form secondary amine group(s). A preferred aliphatic alkylene polyamine comprises an aliphatic straight-chain acyclic (C.sub.2 to C.sub.60) alkylene polyamine.

[0264] A highly preferred class of aliphatic alkylene polyamine(s) comprises the polyalkylene polyamine(s), especially the polyethylene polyamine(s). The polyalkylene polyamine(s) comprise at least 3 amine groups, wherein at least one of the amine groups is a primary amine group and at least one of the amine groups is a secondary amine group.

[0265] Preferably, the polyalkylene polyamine contains at least 4, and typically from 4 to 60, preferably 4 to 40, more preferably 4 to 20, even more preferably 4 to 12, especially 4 to total carbon atoms.

[0266] Suitably, the polyalkylene polyamine contains at least three amine groups, and typically from 3 to 12, preferably 3 to 10, more preferably 3 to 8, even more preferably 3 to 6, total amine groups. Highly preferred polyalkylene polyamines include 3, 4, 5, 6, 7, or 8 total amine groups, especially 3, 4, 5, or 6 total amine groups.

[0267] Suitably, each nitrogen atom of the polyalkylene polyamine may independently represent a primary, secondary, or tertiary amine group.

[0268] Preferably, the polyalkylene polyamine includes at least two primary amine groups. More preferably, the polyalkylene polyamine has a total number of two primary amine groups.

[0269] The polyalkylene polyamine includes at least one secondary amine group, and typically from 1 to 10, preferably 1 to 8, more preferably 1 to 7, even more preferably 1 to 6, even more preferably 1 to 5, even more preferably 1 to 4, secondary amine group(s).

[0270] Preferably, the polyalkylene polyamine, includes only two primary amine group and all of the remaining amine group(s) are secondary amine group(s).

[0271] The polyalkylene polyamine(s) may be represented by a compound of formula II

##STR00003## [0272] wherein: each R.sup.2 independently represents at each occurrence hydrogen, C.sub.1 to C.sub.12 alkyl group, C.sub.2 to C.sub.6 alkenyl group or C.sub.1 to C.sub.12 alkyl amine; R.sup.3 and R.sup.4 each independently represent hydrogen, C.sub.1 to C.sub.12 alkyl group, C.sub.2 to C.sub.6 alkenyl group or C.sub.1 to C.sub.12 alkyl amine; a is an integer from 0 to 10; each n independently represents at each occurrence an integer from 2 to 6; and with the proviso that when a is 0 then at least one of R.sup.3 or R.sup.4 represents hydrogen.

[0273] Preferably, each R.sup.2 in a compound of formula II independently represents at each occurrence hydrogen, C.sub.1 to C.sub.12 alkyl group or C.sub.1 to C.sub.12 alkyl amine such as (CH.sub.2).sub.nN(R.sup.3)R.sup.4 where n, R.sup.3 and R.sup.4 are as defined herein. More preferably, each R.sup.2 in a compound of formula II independently represents at each occurrence hydrogen or C.sub.2 to C.sub.6 alkyl amine, for example (CH.sub.2).sub.nN(R.sup.3)R.sup.4 where n is 2 to 6 and R.sup.3 and R.sup.4 are as defined herein. Even more preferably, each R.sup.2 in a compound of formula II independently represents at each occurrence hydrogen or C.sub.2 to C.sub.4 alkyl amine, for example (CH.sub.2).sub.nN(R.sup.3)R.sup.4 where n is 2 to 4 and R.sup.3 and R.sup.4 are as defined herein. Most preferably, each R.sup.2 in a compound of formula II independently represents at each occurrence hydrogen or C.sub.2H.sub.4NH.sub.2 (i.e., aminoethyl), especially hydrogen.

[0274] Preferably, R.sup.3 in a compound of formula II represents hydrogen or C.sub.1 to C.sub.6 alkyl group, especially hydrogen.

[0275] Preferably, R.sup.4 in a compound of formula II represents hydrogen or C.sub.1 to C.sub.6 alkyl group, especially hydrogen.

[0276] Preferably, a in a compound of formula II is an integer from 1 to 6, more preferably 1 to 4, especially 3.

[0277] Preferably, each n in a compound of formula II independently represents at each occurrence an integer from 2 to 4.

[0278] Preferably, each n in a compound of formula II is identical.

[0279] Most preferably each n in a compound of formula II is 2.

[0280] Non-limiting examples of suitable polyalkylene polyamine compounds include: polyethylene polyamines such as diethylene triamine; triethylene tetramine; tetraethylene pentamine; pentaethlyene hexamine; N.sup.2-(aminoethyl)triethylene tetramine; and polypropylene polyamines such as di-(1,2-propylene) triamine; di(1,3-propylene) triamine; and mixtures thereof.

[0281] A most preferred polyalkylene polyamine is a polyethylene polyamine (i.e., unsubstituted polyethylene polyamine). Preferred specific polyethylene polyamines include: diethylene triamine; triethylene tetramine; tetraethylene pentamine; and pentaethlyene hexamine; and mixtures thereof. Diethylene triamine, tetraethylene pentamine, and pentaethylne hexamine are especially preferred.

[0282] The most preferred polyethylene polyamine is tetraethylene pentamine.

[0283] The aliphatic alkylene polyamines may be obtained from commercial suppliers such as Delamine BV or Huntsman Ethylene Amines Ltd.

[0284] Commercial mixtures of amine compounds may advantageously be used. For example, one process for preparing polyalkylene polyamines involves the reaction of an alkylene dihalide (e.g., ethylene dichloride or propylene dichloride) with ammonia which may result in a complex mixture wherein pairs of nitrogen atoms are joined by alkylene groups, forming such compounds as tetraethylene pentamine, N.sup.2-(aminoethyl)triethylene tetramine and the isomeric piperazines, such as N-(2-(4-(2-aminoethyl)piperazin-1-yl)ethyl)ethanediamine and N.sup.1-(2-aminoethyl)-N.sup.2-(2-(piperazin-1-yl)ethyl)ethane-1,2-diamine.

[0285] A highly preferred aliphatic alkylene polyamine compound is tetraethylene pentamine. The tetraethylene pentamine may be employed singly. Alternatively, the tetraethylene polyamine may form part of a mixture of polyamines, for example, the mixture of polyamines may include, in addition to tetraethylene polyamine, N.sup.2-(aminoethyl)triethylene tetramine and the isomeric piperazines, such as N-(2-(4-(2-aminoethyl)piperazin-1-yl)ethyl)ethanediamine and N.sup.1-(2-aminoethyl)-N.sup.2-(2-(piperazin-1-yl)ethyl)ethane-1,2-diamine.

[0286] Suitably, when the aliphatic alkylene polyamine compound comprises a mixture of at least two or more aliphatic alkylene polyamines, as defined hereinbefore, such a mixture may include tetraethylene pentamine and N.sup.2-(aminoethyl)triethylene tetramine.

(B)(iii)(b) Aliphatic Hydrocarbyl-Substituted Monocarboxylic Acid

[0287] The aliphatic alkylene polyamine (B)(iii)(a), as defined herein, may be reacted with an aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) to form said aliphatic hydrocarbyl acid amide Additive (B)(iii). The reaction is conducted in a manner and under conditions sufficient to react at least one amine group of the aliphatic alkylene polyamine (B)(iii)(a) with the aliphatic hydrocarbyl mono acid or derivative thereof (B)(iii)(b) of formula I to form at least one amide bond.

[0288] Suitably, it will be appreciated that the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) has a total number of from 10 to 30 carbon atoms comprising 9 to 29 carbon atoms of the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituent and 1 carbon atom from the acidic carbonyl group.

[0289] Suitably, the aliphatic (C to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) may be represented by a compound of formula I:

##STR00004## [0290] wherein R.sup.1 represents a C.sub.9 to C.sub.29 aliphatic hydrocarbyl group and X represents-OH or a suitable leaving group in a compound of formula I.

[0291] Suitable leaving groups which X may represent include-OC(O)R.sup.1, OR.sup.5 or halo wherein R.sup.1 represents a C.sub.9 to C.sub.29 aliphatic hydrocarbyl group as defined herein and R.sup.5 represents a C.sub.1 to C.sub.8 aliphatic hydrocarbyl group. More preferably, X represents OH or OC(O)R.sup.1 i.e., the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl monocarboxylic acid or anhydride derivative thereof. Most preferably, X represents-OH in a compound of formula I, i.e., the compounds of formula I represent an aliphatic (C.sub.9 to C.sub.29) hydrocarbyl monocarboxylic acid having a terminal carboxylic acid group.

[0292] R.sup.1 in a compound of formula I represents a C.sub.9 to C.sub.29 aliphatic hydrocarbyl group, preferably a C.sub.11 to C.sub.23 aliphatic hydrocarbyl group, even more preferably a Cis to C.sub.20 aliphatic hydrocarbyl group, even more preferably a C.sub.16 to C.sub.18 aliphatic hydrocarbyl group, especially a C.sub.17 aliphatic hydrocarbyl group.

[0293] Suitably, the aliphatic hydrocarbyl group which R.sup.1 represents in a compound of formula 1 may be saturated or unsaturated, acrylic or part acrylic and part cyclic, or straight chain or branched chain. Preferably, the aliphatic hydrocarbyl group which R.sup.1 represents in a compound of formula 1 is a saturated or unsaturated acrylic hydrocarbyl group, which hydrocarbyl group may be straight chain or branched chain.

[0294] Preferred aliphatic hydrocarbyl groups which R.sup.1 may represent include alkyl and alkenyl groups.

[0295] Accordingly, in an embodiment, the aliphatic hydrocarbyl groups which R.sup.1 may represent comprises a C to C.sub.29, preferably a C.sub.11 to C.sub.23, even more preferably a C.sub.15 to C.sub.20, even more preferably a C.sub.16 to C.sub.18, especially a C.sub.17, alkyl group, which alkyl group may be straight or branched chain, and/or which alkyl group is an acyclic alkyl group.

[0296] Accordingly, in an alternative embodiment, the aliphatic hydrocarbyl groups which R.sup.1 may represent comprises a C.sub.9 to C.sub.29, preferably a C.sub.11 to C.sub.23, even more preferably a C.sub.15 to C.sub.20, even more preferably a C.sub.16 to C.sub.18, especially a C.sub.17, alkyl group, which alkyl group may be straight or branched chain, and/or which alkenyl group is an acyclic alkenyl group.

[0297] Representative examples of a compound of formula I include the mono-carboxylic acids (e.g., fatty acids) such as: a nonanoic acid (e.g., perlargonic); a decanoic acid (e.g., capric); an undecanoic acid; a dodecanoic acid (e.g., lauric); a tridecanoic acid; a tetradecanoic acid (e.g., myristic acid); a pentadecanoic acid; a heaxdecanoic acid (e.g., palmitic); a heptadecanoic acid (e.g., margaric); an octadecanoic acid (such as stearic and isostearic); a nonadecanoic acid; an eicosanic acid (e.g., arachidic); a docosanoic acid (e.g., behenic); a tetracosanoic acid (e.g lignoceric); a hexacosanoic acid (e.g., cerotic); a nonenoic acid; a decanoic acid; an undecanoic acid; a dodecenoic acid; a tridecanoic acid; a pentadecanoic acid; a hexadecenoic acid; a heptadecenoic acid; an octadecenoic acid (e.g., oleic); and all structural isomers, all stereoisomers, and mixtures thereof.

[0298] Accordingly, highly preferred aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid(s) or derivatives thereof (B)(iii)(b) include mono-carboxylic acids of formula I, wherein said mono-carboxylic acid(s) has a total number of from 10 to 30, preferably a 12 to 24, even more preferably 16 to 20, especially 18 carbon atoms, and said hydrocarbyl substituent comprises an acyclic alkyl or acyclic alkenyl group.

[0299] The most preferred aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid(s) (B)(iii)(b) include mono-carboxylic acids of formula I, wherein said mono-carboxylic acids has a total number of 18 carbon atoms and said hydrocarbyl substituent comprises an acyclic alkyl or acyclic alkenyl group. Examples of such acids include octadecanoic acid and octa decanoic acid, and all structural and stereoisomers. Specific examples of such acids include stearic acid, isostearic acid (i.e., 16-methyl heptadecanoic acid), 9-octadecenoic acid, such as oleic acid.

[0300] The most preferred aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid(s) (B)(iii)(b) is isostearic acid.

[0301] The reaction of the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) with the aliphatic alkylene polyamine (B)(iii)(a) to form said aliphatic hydrocarbyl acid amide (B)(iii) is typically carried out at an elevated temperature, for approximately 2 to 10 hours, and optionally in the presence of a suitable solvent, e.g., toluene. Typically the reaction is performed at a temperature of between 100? C. to 250? C., more preferably 120? C. to 200? C., and any water produced during the condensation reaction (i.e., when X represents-OH in a compound of formula I) is removed, for example, using a Dean Stark apparatus. As a result of water formed in-situ by the amidation reaction, most, if not all, of the imidazoline groups are intentionally hydrolysed to primary amine groups. Suitable methods for reacting a compound of formula I with the aliphatic alkylene polyamine (B)(iii)(a) to form the aliphatic hydrocarbyl acid amide (B)(iii) additive component are described in U.S. Pat. Nos. 5,395,539 and 4,705,643.

[0302] Accordingly, during reaction of the aliphatic (C to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) with the aliphatic alkylene polyamine (B)(iii)(a) sufficient amount of the compound of formula I is employed to impart oil-solubility or oil-dispersibility to the resulting aliphatic hydrocarbyl acid amide (B)(iii) additive component. Suitably, the molar ratio of the aliphatic (C to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) of formula I the aliphatic alkylene polyamine (B)(iii)(a) is from about 2 to 10, preferably 3 to 10, most preferably 3 to 5, especially 3 to 4 molar equivalents of the compound of formula I reacted per mole of aliphatic alkylene polyamine (B)(iii)(a). Suitably, sufficient amount of the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) of formula I is employed so that the resultant aliphatic alkylene polyamine (B)(iii)(a) has at least one reactive amine group, i.e., a primary or secondary amine group. Thus, for example, when the most preferred isostearic acid is reacted with the most preferred tetraethylene pentamine (containing 5 reactive amine groups), then three molar equivalents of isostearic acid are preferably reacted per mole of tetraethylene pentamine, with the condensation reaction yielding a product mixture but with condensation preferentially taking place at the two primary amine groups and optionally one of the secondary amine groups of the tetraethylene pentamine.

[0303] Thus, for example, the reaction between isostearic acid and tetraethylene pentamine, may be represented by the following equation:

##STR00005## [0304] where product mixture represents a mixture of products including those of formulae III, IV, V, VI, and VII below:

##STR00006##

[0305] As a result of water formed in-situ by the amidation reaction, most, if not all, of the imidazoline groups of structures V, VI and VII are intentionally hydrolysed to amine groups.

[0306] Accordingly, preferred aliphatic acid amide additive(s) (B)(iii) is obtainable by reaction of a aliphatic alkylene polyamine (B)(iii)(a), as defined and identified herein, and (B)(iiii)(c) a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) and (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s). Preferably, (B)(iii)(a) the aliphatic alkylene polyamine comprises a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total amine groups, as defined and identified herein. More preferred aliphatic acid amide additive(s) (B)(iii) is obtainable by reaction of (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof, as defined and identified herein, and (B)(iii)(a) a polyethylene polyamine, as defined and identified herein. Even more preferred acid amide additive(s)(B)(iii) is obtainable by reacting (B)(iii)(b) isostearic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms, as defined and identified herein, especially tetraethylene pentaamine.

(B)(iii)(c) Aliphatic Hydrocarbyl-Substituted Anhydride

[0307] The aliphatic hydrocarbyl acid imide additive (B)(iii) is obtainable by reaction of the aliphatic alkylene polyamine (B)(iii)(a), as defined herein, and an aliphatic hydrocarbyl-substituted acid anhydride, an aliphatic hydrocarbyl-substituted di-acid or an aliphatic hydrocarbyl-substituted diol (B)(iii)(c).

Preferred Alkylene Polyamine(s) (B)(iii)(a) Used to Form Additive (B)(iii)

[0308] Preferred aliphatic alkylene polyamine(s) (B)(iii)(a) which may be reacted with reactants (B)(iii)(c), including preferred embodiments I and II, to form the aliphatic acid imide additive (B)(iii) comprise the polyalkylene polyamine(s), especially polyethylene polyamine(s), as defined hereinbefore, such as the polyalkylene polyamines represented by a compound of formula I.

[0309] Non-limiting examples of suitable polyalkenyl polyamine compounds include: polyethylene polyamines such as diethylene triamine; triethylene tetramine; tetraethylene pentamine; pentaethlyene hexamine; and mixtures thereof. Diethylene triamine, tetraethylene pentamine and pentaethlyene hexamine are particularly preferred.

Embodiment I

[0310] In an embodiment, the aliphatic acid imide additive (B)(iii) is obtainable by reaction of an aliphatic alkylene polyamine (B)(iii)(a), as defined herein, and additive (B)(iii)(c) which is a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted diacid, as defined herein (i.e., additive (B)(ii), as defined herein is used as (B)(iii)(c)).

[0311] Suitably, preferred aliphatic alkylene polyamine(s) (B)(iii)(a) which may be used to form additive (B)(iii) are as defined and identified herein before.

[0312] Suitably, the preferred poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) or poly(C.sub.2 to C.sub.6)alkenyl-substituted diacid(s) (B)(ii), as defined and identified herein, is used as reactant (B)(iii)(c) to form Additive (B)(iii).

[0313] Preferably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) which may be used as (B)(iii)(c) to form Additive (B)(iii) comprise poly(C.sub.2 to C.sub.6)alkenyl-substituted succinic anhydride, such as poly(ethylenyl) succinic anhydride(s), poly(propylenyl) succinic anhydride(s), poly(butenyl) succinic anhydride(s), poly(isobutenyl) succinic anhydride(s) or combinations thereof. The most preferred poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) comprise polyisobutenyl-substituted succinic anhydride(s) (PIBSA).

[0314] Preferably, the poly(C.sub.2 to C.sub.6)alkenyl-substituted diacid(s) which may be used as (B)(iii)(c) to form Additive (B)(iii) comprise poly(C.sub.2 to C.sub.6)alkenyl-substituted succinic acid(s), such as poly(ethylenyl) succinic acid(s), poly(propylenyl) succinic acid(s), poly(butenyl) succinic acid(s), poly(isobutenyl) succinic acid(s) or combinations thereof. The most preferred poly(C.sub.2 to C.sub.6)alkenyl-substituted diacid(s) comprise polyisobutenyl-substituted succinic acid(s).

[0315] Preferably, the number average molecular weight (Mn) of the poly(C.sub.2 to C.sub.6)alkenyl substituent group of said poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) or poly(C.sub.2 to C.sub.6)alkenyl-substituted diacid(s) which may be used as (B)(iii)(c), particularly the number average molecular weight (Mn) of the polyisobutenyl substituent group of the preferred polyisobutenyl-substituted succinic anhydride(s) or polyisobutenyl-substituted succinic acid(s), is a defined hereinbefore with reference to Additive (B)(ii).

[0316] Suitably, the ratio of the weight average molecular weight (M.sub.w) to number average molecular weight (M.sub.n), i.e., M.sub.w/M.sub.n, of the poly(C.sub.2 to C.sub.6)alkenyl substituent group(s) of said poly(C.sub.2 to C.sub.6)alkenyl-substituted acid anhydride(s) or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid(s), is as defined hereinbefore with reference to Additive (B)(ii).

[0317] Suitably, the average succination ratio of the one or more poly(C.sub.2 to C.sub.6)alkenyl succinic anhydride(s), especially said one or more polyisobutenyl succinic anhydride(s), is as defined hereinbefore with reference to Additive (B)(ii).

[0318] Accordingly, a highly preferred Additive (B)(ii) which may be used as (B)(iii)(c) to form additive (B)(iii) comprises a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid having a Mn of from 400 to 4000 daltons, particularly a polyisobutenyl succinic anhydride having a Mn of from 400 to 4000 daltons, especially 400 to 3000 daltons.

[0319] Preparative methods for forming the aliphatic acid imide Additive (B)(iii) from reaction of an aliphatic alkylene polyamine (B)(iii)(a) and (B)(iii)(c) are described, for example, in U.S. Pat. Nos. 6,734,148 and 6,743,757. Suitable aliphatic acid imide additive(s) (B)(iii) of Embodiment I are available from Infineum UK Ltd.

[0320] Accordingly, preferred aliphatic acid imide additive(s) (B)(iii) is obtainable by reaction of a polyethylene polyamine (B)(iii)(a), as defined and identified herein, and (B)(iii)(c) a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid having a Mn of from 400 to 4000 daltons, as defined and identified herein. More preferred aliphatic acid imide additive(s) (B)(iii) is obtainable by reaction of a polyethylene polyamine (B)(iii)(a) having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms and (B)(iii)(c) a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid having a Mn of from 400 to 3000 daltons.

Embodiment II

[0321] In an alternative embodiment, the aliphatic acid imide additive (B)(iii) is obtainable by reaction of an aliphatic alkylene polyamine (B)(iii)(a), as defined and identified herein, and (B)(iii)(c) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride, an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid, or an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diol.

[0322] Preferably, (B)(iii)(c) comprises an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted succinic anhydride, an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted succinic acid, or an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted 1,4-diol.

[0323] Preferably, the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl group substituent(s) of said anhydride, diacid or diol (B)(iii)(c) comprises aliphatic (C.sub.12 to C.sub.24) hydrocarbyl groups, even more preferably aliphatic (C.sub.16 to C.sub.20) hydrocarbyl groups, even more preferably aliphatic (C.sub.16 to C.sub.18) hydrocarbyl groups, especially aliphatic (C.sub.18) hydrocarbyl groups. Preferred hydrocarbyl group(s) substituent groups of said aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride, aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid, or aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diol (B)(iii)(c), as defined herein, include alkyl and/or alkenyl groups more preferably acyclic alkyl and/or acyclic alkenyl groups. Suitably, said alkyl and/or alkenyl groups may be straight chain or branched chain, and includes all structural isomers and/or stereoisomers.

[0324] Accordingly, highly preferred aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride(s) comprise (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) and (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s), more preferably (C.sub.12 to C.sub.24)alkyl-substituted succinic anhydride(s) and (C.sub.12 to C.sub.24)alkenyl-substituted succinic anhydride(s), even more preferably (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) and (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s), even more preferably (C.sub.16 to C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.16 to C.sub.18)alkenyl-substituted succinic anhydride(s), especially (C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.18)alkenyl-substituted succinic anhydride(s).

[0325] Accordingly, highly preferred aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s) comprise (C.sub.10 to C.sub.30)alkyl-substituted succinic acid(s) and (C.sub.10 to C.sub.30)alkenyl-substituted succinic acid(s), more preferably (C.sub.12 to C.sub.24)alkyl-substituted succinic acid(s) and (C.sub.12 to C.sub.24)alkenyl-substituted succinic acid(s), even more preferably (C.sub.16 to C.sub.20)alkyl-substituted succinic acid(s) and (C.sub.16 to C.sub.20)alkenyl-substituted succinic acid(s), even more preferably (C.sub.16 to C.sub.18)alkyl-substituted succinic acid(s) and (C.sub.16 to C.sub.18)alkenyl-substituted succinic acid(s), especially (C.sub.18)alkyl-substituted succinic acid(s) and (C.sub.18)alkenyl-substituted succinic acid(s).

[0326] Accordingly, highly preferred aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diol(s) comprise (C.sub.10 to C.sub.30)alkyl-substituted 1,4-diol(s) and (C.sub.10 to C.sub.30)alkenyl-substituted 1,4-diol(s), more preferably (C.sub.12 to C.sub.24)alkyl-substituted succinic 1,4-diol(s) and (C.sub.12 to C.sub.24)alkenyl-substituted 1,4-diol(s), even more preferably (C.sub.16 to C.sub.20)alkyl-substituted 1,4-diol(s) and (C.sub.16 to C.sub.20)alkenyl-substituted 1,4-diol(s), even more preferably (C.sub.16 to C.sub.18)alkyl-1,4-diol(s) and (C.sub.16 to C.sub.18)alkenyl-substituted 1,4-diol(s), especially (C.sub.18)alkyl-substituted 1,4-diol(s) and (C.sub.18)alkenyl-substituted 1,4-diol(s).

[0327] Most preferred are the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride(s) and aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s), as defined herein, especially the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride(s), more especially the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted succinic anhydride(s).

[0328] Suitably, the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride(s), the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s), and the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diol(s), as defined herein, may be represented by a compound of formula IIIa, formula IIIb and formula IIIc, respectively:

##STR00007##

wherein R.sup.5 represents a C.sub.5 to C.sub.29 aliphatic hydrocarbyl group, R.sup.6 represents H or a C.sub.3 to C.sub.14 aliphatic hydrocarbyl group, wherein the total number of carbon atoms present in a combination of groups R.sup.5 and R.sup.6 is from 9 to 29 (i.e., the hydrocarbyl substituent groups include from 10 to 30 carbon atoms).

[0329] Preferably, the total number of carbons present in a combination of groups R.sup.5 and R.sup.6 is from 11 to 23, more preferably 15 to 20, even more preferably 16 to 18, especially 17.

[0330] Preferably, R.sup.5 in a compound of formula I represents a C.sub.5 to C.sub.29 alkyl or C.sub.5 to C.sub.29 alkenyl group, preferably a C.sub.5 to C.sub.23 alkyl or C.sub.5 to C.sub.23 alkenyl group, even more preferably a C.sub.7 to C.sub.20 alkyl or C.sub.7 to C.sub.20 alkenyl group, even more preferably a C.sub.7 to C.sub.17 alkyl or C.sub.7 to C.sub.17 alkenyl group.

[0331] Preferably, R.sup.6 in a compound of formula I represents hydrogen or a C.sub.3 to C.sub.14 alkyl or C.sub.3 to C.sub.14 alkenyl group, preferably hydrogen or a C.sub.3 to C.sub.12 alkyl or C.sub.3 to C.sub.12 alkenyl group, preferably hydrogen or a C.sub.3 to C.sub.10 alkyl or C.sub.3 to C.sub.10 alkenyl group.

[0332] Accordingly, the aliphatic acid imide additive (B)(iii) may be represented by a compound of formula IV:

##STR00008##

wherein R.sup.5 and R.sup.6 are each as defined for a compound of formula IIIa, IIIb and IIIc, and Nis derived from the primary amine (NH.sub.2) group of the aliphatic alkylene polyamine (B)(iii)(a) and X represents the remainder of the aliphatic alkylene polyamine (B)(iii)(a).

[0333] Suitably, the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted acid anhydride(s), an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s), or an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diol(s) (B)(iii)(c) may be prepared by standard techniques known in the art, such as in a similar manner as described in relation to the preparation of additive (B)(ii), defined herein. For example, compounds (B)(iii)(c) may be prepared by functionalisation of the appropriate alkene with mono-unsaturated reactants, such as mono- and dicarboxylic acid material, i.e., acid, or acid derivative material, including (i) monounsaturated C.sub.4 to C.sub.10 dicarboxylic acid wherein (a) the carboxyl groups are vicinyl, (i.e., located on adjacent carbon atoms) and (b) at least one, preferably both, of the adjacent carbon atoms are part of the mono unsaturation; and (ii) derivatives of (i) such as anhydrides or C.sub.1 to C.sub.5 alcohol derived mono- or diesters of (i). Mixtures of monounsaturated carboxylic materials (i) and (ii) also may be used. Upon reaction with the backbone, the monounsaturation of the monounsaturated carboxylic reactant becomes saturated. Thus, for example, maleic anhydride becomes substituted succinic anhydride. Exemplary of such monounsaturated carboxylic reactants are fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, chloromaleic anhydride, and lower alkyl (e.g., C.sub.1 to C.sub.4 alkyl) acid esters of the foregoing, e.g., methyl maleate, ethyl fumarate, and methyl fumarate.

[0334] Still further, aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s) may be prepared by hydrolysis of the corresponding aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted anhydride(s), and the aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diacid(s) may be converted into the corresponding aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted diols(s).

[0335] Accordingly, preferred aliphatic acid imide additive(s) (B)(iii) is obtainable by reaction of a polyethylene polyamine (B)(iii)(a), as defined and identified herein, and (B)(iii)(c) a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) and (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s), as defined and identified herein. More preferred aliphatic acid imide additive(s) (B)(iii) is obtainable from reaction of a polyethylene polyamine (B)(iii)(a) having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms, as defined and identified herein, and (B)(iii)(c) a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) and (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s), as defined and identified herein, preferably (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) and (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s), especially (C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.18)alkenyl-substituted succinic anhydride(s).

Three-Way Additive Composition

[0336] Suitably, introduction of the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) into a crude oil may be accomplished by: (i) separate introduction of each additive; (ii) introduction of a two-way combination of additives and separate introduction of the third additive; or, (iii) essentially simultaneous introduction of each three additives (B)(i), (B)(ii) and (B)(iii). Essentially simultaneous introduction of each three additives is preferred and this may be accomplished by introduction of an additive composition comprising the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) into a crude oil.

[0337] Accordingly, the present invention provides an additive composition suitable for introduction into to a crude oil having an asphaltene content to inhibit precipitation of asphaltene(s) from the crude oil, the additive composition comprising or made by admixing: a hydrocarbon diluent fluid; and a three-way combination of each of said additive(s) (B)(i), (B)(ii) and (B)(iii) as defined and identified herein.

[0338] Examples of suitable hydrocarbon diluent fluids include mineral oils and hydrocarbonaceous solvents. Suitable hydrocarbonaceous solvents include aromatic solvents such as the commercial mixed aromatic solvents Solvesso? and Shellsol?, and aliphatic solvents such as isoalkanes, including Isopar? L. Other suitable solvents known in the art may be used, such as Norpar? (pentanes), Exxsol? (dearomatised hydrocarbon fluids), Nappar? (naphthenics), Varsol? (non-dearomatised hydrocarbon fluids), xylenes, and HAN 8080? (aromatic solvent).

[0339] The additive composition may further contain a hydrophobic oil solubilizer and/or a dispersant for the additive(s). Such solubilizers may include, for example, surfactants and/or carboxylic acid solubilizers.

[0340] The compositions may further include, for example, viscosity index improvers, anti-foamants, antiwear agents, demulsifiers, anti-oxidants, and other corrosion inhibitors.

[0341] The additive composition may comprise the additive components of (B)(i), (B)(ii) and (B)(iii) (such as a three-way additive combination of (B)(i), (B)(ii) and (B)(iii)), diluent, and optional hydrophobic oil solubilizer and/or a dispersant for the additive(s), viscosity index improvers, anti-foamants, antiwear agents, demulsifiers, anti-oxidants, and other corrosion inhibitors and the additive composition may be absent additional components, i.e., additional components are present at 0 wt %, based upon the weight of the additive composition, or if present in the additive composition, the component is present at levels that do not impact the additive composition properties, such as less than 10 ppm, or less than 1 ppm or less than 0.001 ppm.

Selected Embodiments

[0342] Embodiments of the invention include: [0343] Embodiment 1. A method for inhibiting precipitation of asphaltene(s) from a crude oil having an asphaltene content, the method comprising: [0344] (A) providing a crude oil in a major amount, the crude oil having an asphaltene content; and [0345] (B) introducing into the crude oil a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), in an effective minor amount, to inhibit precipitation of asphaltene(s) from the crude oil, wherein the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) comprises or is made by admixing: [0346] (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; [0347] (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and [0348] (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine. [0349] Embodiment 2. A method for improving the transportation of a crude oil, the method comprising the steps of: (i) introducing a minor amount of a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), as defined in Embodiment 1, into (A) a major amount of a crude oil having an asphaltene content; and (ii) transporting said crude oil. [0350] Embodiment 3. A method of preparing a crude oil composition comprising introducing a minor amount of a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), as defined in Embodiment 1, into a major amount of a crude oil having an asphaltene content. [0351] Embodiment 4. A crude oil composition comprising or made by admixing: (A) a crude oil having an asphaltene content in a major amount; and (B) a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), as defined in Embodiment 1, in a minor amount. [0352] Embodiment 5. An additive composition suitable for introduction into to a crude oil having an asphaltene content to inhibit precipitation of asphaltene(s) from the crude oil, the additive composition comprising or made by admixing: a hydrocarbon diluent fluid; and a three-way combination of each of said additive(s) (B)(i), (B)(ii) and (B)(iii), as defined in Embodiment 1. [0353] Embodiment 6. Use of a three-way combination of additives (B)(i), (B)(ii) and (B)(iii), as defined in Embodiment 1, in an effective minor amount in a crude oil having an asphaltene content to inhibit deposition of asphaltene(s) from the crude oil. [0354] Embodiment 7. Use of Embodiment 6, wherein the combination of additives (B)(i), (B)(ii) and (B)(iii) are in the form of a crude oil additive composition. [0355] Embodiment 8. Any one of Embodiments 1 to 7, wherein the ratio of the total combined individual amounts of additives (B)(i) and (B)(ii) on a mass % active ingredient basis to total amount of additive(s) (B)(iii) on a mass % active ingredient basis in the crude oil, based on the total amount of crude oil, is in the range of 8:1 to 1:1. [0356] Embodiment 9. Any one of Embodiments 1 to 8, wherein the treat rate of the three-way additive combination of (B)(i), (B)(ii) and (B)(iii) is greater than or equal to 75 ppm by mass based on the total mass of crude oil. [0357] Embodiment 10. Any one of Embodiments 1 to 9, wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent (B)(i) comprises an alkaline earth metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent. [0358] Embodiment 11. Any one of Embodiments 1 to 10, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent comprises a calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent. [0359] Embodiment 12. Any one of Embodiments 1 to 11, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent has a total base number (TBN) at 100% active mass of less than or equal to 100, preferably less than or equal to 75, mg KOH/g as measured by ASTM D2896. [0360] Embodiment 13. Any one of Embodiments 1 to 12, wherein said poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii) comprises a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid. [0361] Embodiment 14. Any one of Embodiments 1 to 13, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises an alkylene polyamine having from 2 to 20 total number of carbon atoms and from 2 to 12 amine groups. [0362] Embodiment 15. Any one of Embodiments 1 to 14, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises a polyethylene polyamine. [0363] Embodiment 16. Any one of Embodiments 1 to 15, wherein the aliphatic (C.sub.9 to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) used to obtain said aliphatic hydrocarbyl acid amide (B)(iii) comprises a (C.sub.9 to C.sub.29)alkyl-substituted monocarboxylic acid or derivative thereof or (C to C.sub.29)alkenyl-substituted monocarboxylic acid or derivative thereof, preferably a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof. [0364] Embodiment 17. Any one of Embodiments 1 to 16, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride(s), a poly(C.sub.2 to C.sub.6)alkenyl-substituted di-acid(s), or a poly(C.sub.2 to C.sub.6)alkenyl-substituted diols(s), preferably a polyisobutenyl succinic anhydride(s) or polyisobutenyl succinic acid(s). [0365] Embodiment 18. Any one of Embodiments 1 to 18, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a (C.sub.10 to C.sub.30)alkyl-substituted anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted anhydride(s), preferably a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s). [0366] Embodiment 19. Any one of Embodiments 1 to 18, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms, as defined and identified herein. [0367] Embodiment 20. Any one of Embodiments 1 to 19, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting said polyethylene polyamine (B)(iii)(a), preferably tetraethylene pentaamine, and (B)(iii)(b) isostearic acid or derivative thereof. [0368] Embodiment 21. Any one of Embodiments 1 to 20, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid imide which is obtainable by reacting (B)(iii)(c) a (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) or (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s), preferably a (C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.18)alkenyl-substituted succinic anhydride(s), and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms. [0369] Embodiment 22. Any one of Embodiments 1 to 21, wherein the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) is introduced into said crude oil during an up-stream or mid-stream crude oil transportation, storage or processing operation. [0370] Embodiment 23. Any one of Embodiments 1 to 22, wherein said crude oil is in the form of a crude oil stream. [0371] Embodiment 24. Any one of Embodiments 1 to 23, wherein said crude oil has been recovered by a secondary or enhanced crude oil recovery process.

[0372] This invention further relates to embodiments: [0373] A1. A composition comprising a three-way combination of additives (B)(i), (B)(ii) and (B)(iii) comprising, consisting of, consisting essentially of or made by admixing: [0374] (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; [0375] (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and [0376] (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine. [0377] A2. An additive composition comprising or made by admixing a hydrocarbon diluent fluid and the three-way combination of each of additive(s) (B)(i), (B)(ii) and (B)(iii) of paragraph A1. [0378] A3. A crude oil composition comprising or made by admixing crude oil containing asphaltenes and the three-way combination of each of additive(s) (B)(i), (B)(ii) and (B)(iii) of paragraph A1. [0379] A4. The composition of paragraph A3, wherein the ratio of the total combined individual amounts of additives (B)(i) and (B)(ii) on a mass % active ingredient basis to total the amount of additive(s) (B)(iii) on a mass % active ingredient basis in the crude oil, based on the total amount of crude oil, is in the range of 8:1 to 1:1. [0380] A5. The composition of paragraph A3 or A4, wherein the three-way additive combination of (B)(i), (B)(ii) and (B)(iii) is present at greater than or equal to 75 ppm by mass based on the total mass of crude oil. [0381] A6. The composition of paragraph A1, A2, A3, A4, or A5, wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent (B)(i) comprises an alkaline earth metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent. [0382] A7. The composition of paragraph A1, A2, A3, A4, or A5, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent comprises a calcium (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent. [0383] A8. The composition of paragraph A6 or A7, wherein the metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted salicylate detergent has a total base number (TBN) at 100% active mass of less than or equal to 100, preferably less than or equal to 75, mg KOH/g as measured by ASTM D2896. [0384] A9. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, or A8, wherein said poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid (B)(ii) comprises a polyisobutenyl succinic anhydride or a polyisobutenyl succinic acid. [0385] A10. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, or A9, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises an alkylene polyamine having from 2 to 20 total number of carbon atoms and from 2 to 12 amine groups. [0386] A11. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, or A10, wherein the aliphatic alkylene polyamine (B)(iii)(a) which is used to obtain said aliphatic hydrocarbyl acid amide or said aliphatic hydrocarbyl acid imide (B)(iii) comprises a polyethylene polyamine. [0387] A12. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, or All, wherein the aliphatic (C to C.sub.29)hydrocarbyl-substituted monocarboxylic acid or derivative thereof (B)(iii)(b) used to obtain said aliphatic hydrocarbyl acid amide (B)(iii) comprises a (C.sub.9 to C.sub.29)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.9 to C.sub.29)alkenyl-substituted monocarboxylic acid or derivative thereof, preferably a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof. [0388] A13. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, All, or A12, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride(s), a poly(C.sub.2 to C.sub.6)alkenyl-substituted di-acid(s), or a poly(C.sub.2 to C.sub.6)alkenyl-substituted diols(s), preferably a polyisobutenyl succinic anhydride(s) or polyisobutenyl succinic acid(s). [0389] A14. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, or A13, wherein the aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol (B)(iii)(c) used to obtain said aliphatic hydrocarbyl acid imide (B)(iii) comprises a (C.sub.10 to C.sub.30)alkyl-substituted anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted anhydride(s), preferably a (C.sub.10 to C.sub.30)alkyl-substituted succinic anhydride(s) or (C.sub.10 to C.sub.30)alkenyl-substituted succinic anhydride(s). [0390] A15. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, or A14, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting (B)(iii)(b) a (C.sub.17)alkyl-substituted monocarboxylic acid or derivative thereof or (C.sub.17)alkenyl-substituted monocarboxylic acid or derivative thereof and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms, as defined and identified herein. [0391] A16. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, or A15, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid amide which is obtainable by reacting said polyethylene polyamine (B)(iii)(a), preferably tetraethylene pentaamine, and (B)(iii)(b) isostearic acid or derivative thereof. [0392] A17. The composition of paragraph A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, All, A12, A13, A14, A15, or A16, wherein Additive (B)(iii) comprises an aliphatic hydrocarbyl acid imide which is obtainable by reacting (B)(iii)(c) a (C.sub.16 to C.sub.20)alkyl-substituted succinic anhydride(s) or (C.sub.16 to C.sub.20)alkenyl-substituted succinic anhydride(s), preferably a (C.sub.18)alkyl-substituted succinic anhydride(s) and (C.sub.18)alkenyl-substituted succinic anhydride(s), and (B)(iii)(a) a polyethylene polyamine having from 4 to 12 total carbon atoms and from 3 to 8, preferably 3 to 6, total nitrogen atoms. [0393] A18. A method for inhibiting precipitation of asphaltene(s) from a crude oil having an asphaltene content, the method comprising: [0394] (A) providing a crude oil in a major amount, the crude oil having an asphaltene content; and [0395] (B) introducing into the crude oil the composition of any of paragraphs A1 to A17. [0396] A19. The method of paragraph A18, wherein the three-way combination of additives (B)(i), (B)(ii) and (B)(iii) is introduced into said crude oil during an up-stream or mid-stream crude oil transportation, storage or processing operation. [0397] A20. The method of paragraph A18 or A19, wherein said crude oil is in the form of a crude oil stream. [0398] A21. The method of paragraph A18, A19 or A20, wherein said crude oil has been recovered by a secondary or enhanced crude oil recovery process. [0399] A22. A method for improving the transportation of a crude oil, the method comprising the steps of: (i) introducing a minor amount of the composition of any of paragraphs A1 to A17, into (A) a major amount of a crude oil having an asphaltene content; and (ii) transporting said crude oil. [0400] A23. A method of preparing a crude oil composition comprising introducing a minor amount of the the composition of any of paragraphs A1 to A17 into a major amount of a crude oil having an asphaltene content. [0401] A24. A crude oil composition comprising or made by admixing: (A) a crude oil having an asphaltene content in a major amount; and (B) the composition of any of paragraphs A1 to A17 in a minor amount. [0402] A25. A method to inhibit deposition of asphaltene(s) from the crude oil comprising combining the composition of any of paragraphs A1 to A17, in an effective minor amount with a crude oil having an asphaltene content and inhibiting the deposition of asphaltene(s) from the crude oil. [0403] A26. A method to inhibit deposition of asphaltene(s) from the crude oil comprising combining the additive composition of paragraph A2 or any of paragraphs A5 to A17 with a crude oil having an asphaltene content and inhibiting the deposition of asphaltene(s) from the crude oil. [0404] A27. A crude oil composition comprising or made by admixing crude oil containing asphaltenes and (B)(i) a metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent, wherein the metal of said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a valency of +1 or +2 and wherein said metal (C.sub.10 to C.sub.40)hydrocarbyl-substituted hydroxybenzoate detergent has a total base number (TBN) at 100% active mass of less than or equal to 135 mg KOH/g as measured by ASTM D2896; [0405] optionally, (B)(ii) a poly(C.sub.2 to C.sub.6)alkenyl-substituted anhydride or poly(C.sub.2 to C.sub.6)alkenyl-substituted acid; and, [0406] optionally, (B)(iii) an aliphatic hydrocarbyl acid amide, or an aliphatic hydrocarbyl acid imide, or a combination thereof, wherein said aliphatic hydrocarbyl acid amide and said aliphatic hydrocarbyl acid imide is each independently obtained by reacting (B)(iii)(a) an aliphatic alkylene polyamine with (B)(iii)(b) an aliphatic (C.sub.10 to C.sub.30)hydrocarbyl-substituted monocarboxylic acid or derivative thereof or with (B)(iii)(c) an aliphatic hydrocarbyl-substituted anhydride, -diacid or -diol, and wherein the aliphatic alkylene polyamine includes at least two carbon atoms and at least two amine groups, wherein at least one of the amine groups is a primary amine group, and each of said amine groups is bonded to a different carbon atom of the aliphatic alkylene polyamine.

EXAMPLES

[0407] The present invention is illustrated by but in no way limited to the following examples.

Components

[0408] The following components as detailed below were used in the examples:

Additive (B)(i)Calcium Hydrocarbyl-Substituted Salicylate Detergent (SD)

[0409] 64SDAn essentially neutral calcium hydrocarbyl-substituted salicylate detergent having a TBN at 100% active mass of 64 mg KOH/g as measured by ASTM D2896. Available from Infineum UK Ltd.

[0410] 225CSDA comparative overbased calcium hydrocarbyl-substituted salicylate detergent having a TBN at 100% active mass of 225 mg KOH/g as measured by ASTM D2896. Available from Infineum UK Ltd.

Additive (B)(ii)Polyisobutenyl Succinic Anhydride

[0411] PIBSAA polyisobutenyl succinic anhydride (PIBSA) wherein the number average molecular weight (M.sub.n) of the polyisobutenyl substituent is 950 daltons. Available from Infineum UK Ltd.

Additive (B)(iii) Aliphatic Hydrocarbyl Acid Amides (AA)

[0412] AA 1An aliphatic (C.sub.18)hydrocarbyl acid amide obtainable by reaction of isostearic acid and tertraethylene pentaamine. Available from Infineum UK Ltd.

[0413] AA 2An aliphatic (C.sub.18)hydrocarbyl acid amide obtainable by reaction of octadec-9-enoic acid and 1-dimethylamino-3-aminopropane. Available from Arkema as CecaBase 3860.

Additive (B)(iii) Aliphatic Hydrocarbyl Acid Imides (AI)

[0414] AI 1An aliphatic hydrocarbyl acid imide obtainable by reaction of octadecenyl substituted succinic anhydride and tetraethylene pentaamine. Available from Infineum UK Ltd.

[0415] AI 2An aliphatic hydrocarbyl acid imide obtainable by reaction of octadecenyl substituted succinic anhydride and diethylene triamine. Available from Infineum UK Ltd.

[0416] AI 3An aliphatic hydrocarbyl acid imide obtainable by reaction of a polyisobutenyl succinic acid or anhydride wherein the number average molecular weight (Mn) 20 of the polyisobutenyl substituent is 950 daltons and pentaethylene hexamine. Available from Infineum UK Ltd.

[0417] AI 4An aliphatic hydrocarbyl acid imide obtainable by reaction of a polyisobutenyl succinic acid or anhydride wherein the number average molecular weight (Mn) of the polyisobutenyl substituent is 450 daltons and pentaethylene hexamine. Available from Infineum UK Ltd.

[0418] Isostearic Acid (Acid only used in Comparative Example 10) referenced as ISA in Table 1.

Crude Oil

[0419] A Gulf of Mexico heavy crude oil having an asphaltene content of approximately 7 mass %.

Asphaltene Deposition Test

[0420] Tests were carried out using 40 ml samples of the crude oil. The crude oil alone in the absence of any additives was used as a control. The respective additive or respective combination of additives were introduced into the crude oil so that in each case the combined treat rate of all additives added to crude oil, on an active ingredient basis, was 200 ppm, based on the total mass of the crude oil.

[0421] Composition details of each sample tested, which includes the Control Crude Oil, Comparative Examples 1 to 10, and Inventive Examples 1 to 5, are detailed in Table 1 (ppm by mass). When a sample includes a two-way combination of additives comprising (i) a calcium salicylate detergent and (ii) PIBSA (Comparative Examples 2 and 4), then the ratio of the amount of calcium salicylate detergent (mass %) relative to the amount of PIBSA (mass %), on an active ingredient basis, is identical in each sample and is 2.9:1. When a sample includes a three-way combination of additives comprising (i) calcium salicylate detergent, (ii) PIBSA, and (iii) an acid amide (AA 1 or AA2) or acid imide (AI 1 to AI 4) (Inventive Examples 1 to 5, then the ratio the amount of calcium salicylate detergent (mass %) relative to the amount of PIBSA (mass %) relative to the amount acid amide or acid imide (mass %), on an active ingredient basis, is identical in each sample and is 2.9:1:1.3. Accordingly, the ratio of the amount of calcium salicylate detergent (mass %) relative to the amount of PIBSA (mass %) in each sample of the two-way and each sample of three-way combination of additives, on an active ingredient basis, is identical and is 2.9:1.

[0422] The test apparatus comprises a sealable High Pressure High Temperature Pressure (HPHT) cell having a sealable pressure head. The HPTP cell includes a rotateable impeller, a gas charge/gas discharge line to permit the cell to be pressurized with a gas and subsequently depressurized, a pressure recorder, a temperature recorder and a heating element. The impeller is driven by a controllable extra-cellular drive means via a magnetic coupling. Accordingly, the impeller may be rotated at a constant predetermined speed to provide a constant pre-determined sheer force to a crude oil sample in the cell. The HPTP cell permits reproducible evaluation of asphaltene deposition from a crude oil sample at a predetermined specific constant shear rate, at a predetermined specific pressure and a predetermined specific constant temperature, over a predetermined time period.

[0423] An additive or combination of additive(s) was blended with the crude oil (40 ml) at room temperature and pressure before the crude oil was introduced into the HPHT cell. The crude oil sample, containing the additive(s) was then dosed into the HPHT cell. The cell including the crude oil sample was pressurized to 4300 PSI (approximately 310 bar) at 38? C. (approximately 100? Fahrenheit(F)) by introducing a substantially inert hydrocarbon gas, such as Green Canyon gas consisting essentially of methane (87 mole %), ethane (7.5 mole %), propane (3 mole %), butane/iso-butane (1.3 mole %), pentanes (0.4 mole %), and nitrogen (0.4 mole %), into the cell The cell was then heated at 95? C. (approximately 200? F.) for the duration of the test (20 hours) and the impeller driven to provide a shear rate of 1000 s.sup.?1, this provided a constant pressure of 4500 PSI throughout the duration of the test. After 20 hours, the cell is depressurized and allowed to cool to room temperature. The impeller was removed from the cell and dipped (i.e., washed) into methyl ethyl ketone to remove residual crude oil. The dried impeller including asphaltene deposits was then weighed. The % change of asphaltene precipitation from a crude oil sample including one or more additives relative to the crude oil control sample alone (i.e., not including any additives) is calculated according to the following formula: (Deposit mass of sample including additive (mg)/Deposit mass of crude oil control sample?100)?100.

[0424] The results of the tests are presented in Table 1.

[0425] The results demonstrate the following: [0426] 1. The use of a high TBN calcium salicylate detergent (TBN 225 mg KOH/g) alone (Comparative Example 1) provides excellent inhibition of asphaltene deposition. [0427] 2. The use of a two-way additive combination of a high TBN calcium salicylate detergent (TBN 225 mg KOH/g) and PIBSA improves inhibition of asphaltene deposition compared to use of the high TBN calcium detergent alone (compare Comparative Example 2 with Comparative Example 1). [0428] 3. The use of a low TBN calcium salicylate detergent (TBN 64 mg KOH/g) alone (Comparative Example 3) significantly promotes asphaltene deposition from the crude oil (Comparative Example 3). This may be reversed by inclusion of a second PIBSA additive (Comparative Example 4), but the inhibition of asphaltene deposition relative to crude oil alone is marginal and significantly inferior to using the corresponding two-way additive combination including high TBN calcium salicylate detergent (TBN 225 mg KOH/g) (compare Comparative Example 4 with Comparative Example 2). [0429] 4. The acid amides AA 1, AA 2, and acid imide AI 1 inhibit asphaltene deposition from the crude oil to varying extents when the crude oil is dosed with a relatively large amount (200 ppm) of each of these additives (see Comparative Examples 5 to 7). [0430] 5. The use of an inventive three-way combination of additives, such as a calcium salicylate detergent (TBN 64 mg KOH/g), PIBSA and acid amide AA 1 (see Inventive Example 1) or acid imide AI 1 (see Inventive Example 2), provides a significant synergistic inhibition of asphaltene deposition. This synergistic inhibition of asphaltene deposition represents more than a cumulative effect achievable by each additive (compare Inventive Example 1 with Comparative Examples 3, 4 and 5 and compare Inventive Example 2 with Comparative Examples 3, 4 and 7). Furthermore, this synergistic technical effect is achievable by using a relatively low dose of the acid amide AA 1 or acid imide AI 1 in the three-way combination of additives. [0431] 6. The use of an inventive three-way combination of additives, such as a calcium salicylate detergent (TBN 64 mg KOH/g), PIBSA and acid amide AA 1 (see Inventive Example 1) provides a significant synergistic inhibition of asphaltene deposition from crude oil. In contrast, a comparative corresponding three-way combination of additives comprising calcium salicylate detergent (TBN 64 mg KOH/g), PIBSA and isostearic acid (ISA) as a replacement for acid amide AA 1 (see Comparative Example 10) promotes asphaltene deposition from crude oil, thereby evidencing the criticality of the presence of acid amide in the inventive three-way combination of additives to prevent asphaltene deposition. [0432] 7. In contrast, using the same acid amide additive AA 1 or acid imide AI 1 additive in combination with a corresponding two-way combination of additives comprising a high TBN calcium salicylate detergent (TBN 225 mg KOH/g) and PIBSA, thereby producing a corresponding three-way combination of additives, promotes asphaltene deposition from the crude oil relative to the use of the two-way additive combination (compare Comparative Example 8 with comparative Example 2 and Comparative Example 9 with Comparative Example 2). [0433] 8. Further, the use of acid amide AA 1 in combination with a corresponding two-way combination of additives comprising a high TBN calcium salicylate detergent (TBN 225 mg KOH/g) and PIBSA (Comparative Example 8) increases asphaltene deposition from the crude oil, whereas the use of acid amide AA 1 in the inventive combination of additives synergistically reduces asphaltene precipitation from the crude oil (Inventive Example 1). [0434] 9. The use of acid amide AA 2 or each of acid imides AI 2, AI 3 or AI 4, respectively, in an inventive three-way combination of additives including a low TBN calcium salicylate detergent (TBN 64 mg KOH/g) and PIBSA (see inventive Examples 3 to 5), provides a significant inhibition of asphaltene deposition from the crude oil. [0435] 10. The use of PIBSA-PAM acid imide M.sub.n 450 (AI 4, Inventive Example 5)) in the inventive three-way combination of additives provides improved inhibition of asphaltene deposition from the crude oil compared with the use of PIBSA-PAM acid imide M.sub.n 900 (AI 4, Inventive Example 4). [0436] 11. The use of pentaethylene pentaamine to form acid imide (AI 1) in the inventive three-way additive combination (Inventive Example 2) provides improved inhibition of asphaltene deposition compared with using the corresponding acid imide formed from tetraethylene triamine (AI 2, Inventive Example 3).

TABLE-US-00001 TABLE 1 Total Asphal- % Change Treat tene Asphal- 64SD 225CSD PIBSA AA 1 AA 2 A1 1 A1 2 AI 3 AI 4 ISA Rate Deposits tene Example (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) mass (mg) Deposits Crude 200 544 0 Oil Comp 1 ?(200).sup. 200 212 ?61 Comp 2 ?(149).sup. ?(51).sup. 200 179 ?67 Comp 3 ?(200).sup. 200 1229 +126 Comp 4 ?(149).sup. ?(51).sup. 200 457 ?16 Comp 5 ?(200) 200 326 ?40 Comp 6 ?(200) 200 210 ?61 Comp 7 ?(200) 200 473 ?13 Inven- ?(111.5) ?(38.5) ?(50) 200 133 ?75 tive 1 Comp 8 ?(111.5) ?(38.5) ?(50) 200 626 +15 Comp 10 ?(111.5) ?(38.5) ?(50) 200 1285 +136 Inven- ?(111.5) ?(38.5) ?(50) 200 147 ?73 tive 2 Comp 9 ?(111.5) ?(38.5) ?(50) 200 235 ?57 Inven- ?(111.5) ?(38.5) ?(50) 200 275 ?49 tive 3 Inven- ?(111.5) ?(38.5) ?(50) 200 385 ?29 tive 4 Inven- ?(111.5) ?(38.5) ?(50) 200 195 ?64 tive 5