COMPOSITION AND METHOD FOR REDUCING THE VISCOSITY OF HEAVY OIL

Abstract

A composition for reducing the viscosity of heavy oils, comprising a mixture of terpene and petroleum distillate wherein the mixture has a flash point of at least 95° C.

Claims

1. A composition for reducing the viscosity of heavy oils, comprising a mixture of terpene having a flash point of no more than 50° C. and petroleum distillate having a flash point of no more than 85° C., wherein the composition has a flash point of at least 95° C.

2. A composition according to claim 1 wherein the composition has a flash point in the range of from 95° C. to 125° C.

3. A composition according to claim 1 wherein the terpene is selected from the group consisting of limonene, α-pinene, β-pinene, camphene, menthene, turpentine, myrcene, β-caryophyllene, and α-humulene, geraniol, terpineol, myrcene, limonene, pinene, turpentine and mixtures thereof.

4. A composition according to claim 1 wherein the petroleum aliphatic distillate comprises C.sub.11 to C.sub.14 aliphatic hydrocarbons selected from n-alkanes, isoalkanes and cyclic aliphatics and less than 5% w/w aromatics.

5. A composition according to claim 1 wherein the terpene is limonene.

6. A composition according to claim 1 wherein the volume ratio of terpene:petroleum distillate is in the range of from 20:80 to 80:20.

7. A composition according to claim 6 wherein the ratio of terpene:petroleum distillate is in the range of from 20:80 to 50:50.

8. A composition according to claim 1 comprising less than 0.02% w/w of compounds comprising heteroatoms such as sulfur, phosphorus, oxygen and nitrogen.

9. A composition according to claim 1, comprising limonene and C.sub.11 to C.sub.14 petroleum distillate in a volume ratio of limonene: C.sub.11 to C.sub.14 petroleum distillate of from 20:80 to 50:50.

10. A method of reducing the viscosity of heavy oil comprising adding to the heavy oil an effective amount of the composition as claimed in claim 1.

11. A method for pumping heavy oil extracted from an oil well in a geological formation using pumping equipment comprising introducing into said well, formation, or equipment a composition according to claim 1.

12. A method according to claim 10, wherein the composition is added in an amount of from 1% to 30% by volume of the heavy oil.

13. A method according to claim 10, wherein the heavy oil has a viscosity of at least 1000 cPs at 15° C.

14. A method according to claim 10 wherein the heavy oil has a viscosity of at least 5000 cPs at 15° C.

15. A method according to claim 10 wherein the heavy oil has a viscosity of at least 5000 cPs and the composition is added in an amount to provide a viscosity of no more than 1000 cPs at 15° C.

16. A method according to claim 10, wherein the composition is used together with steam in steam assisted gravity drainage.

17. A method according to claim 10 wherein the composition is introduced to a fracture created in a heavy oil geological formation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In the drawings FIG. 1 is a graph showing the change in viscosity of a heavy oil of viscosity 371,000 cPs with percent dilution with Composition 1 of Table 1, as described in Example 2.

EXAMPLE 1

[0045] Compositions in accordance with the invention are prepared by combining the components in the amounts by volume set out in Table 1.

TABLE-US-00001 TABLE 1 Composition Terpene Aliphatic distillate No (proportion by volume) (proportion by volume) 1 d-limonene 35% 65% 2 d-limonene 50% 50% 3 d-limonene 20% 80% 4 d-limonene 25% 75%

[0046] The aliphatic distillate comprises hydrocarbons, C.sub.11-C.sub.14, n-alkanes, isoalkanes, cyclics, <2% aromatics; CAS No. 64742-47-8; Distillates (petroleum) hydrotreated light. [0047] The Flash Point of Composition No. 1 was determined by to be 105° C.

[0048] The individual components have the flash points shown below:

[0049] D80 aliphatic distillate 80° C.

[0050] d-limonene 50° C.

EXAMPLE 2

[0051] This example demonstrates the viscosity reduction of heavy oil provided by the composition of the invention.

[0052] The heavy oil was sourced from a Canadian oil field and found to have a viscosity of 371,000 cPs. Composition 1 of Example 1 was mixed with the heavy oil and the viscosity was determined for various percentages of the Composition 1 in the heavy oil composition.

[0053] The results are shown in Table 2

TABLE-US-00002 TABLE 2 % Comp 1 Viscosity (cPs Temperature (° C.) 0 371000 15.5 1 239000 14.7 3 120000 14.5 5 56388 15.7 10 18896 14.7 15 3215 15 25 661.1 15.2 30 278.3 16.6

[0054] The change in viscosity with percent dilution is shown in the graph which is FIG. 1.