Corrosion inhibitor for various acids

Abstract

A liquid corrosion inhibitor composition for use with acid compositions for use in industrial activities, said corrosion inhibitor composition comprising: a thiourea derivative; a first type of amphoteric surfactant is selected from the group consisting of: a sultaine surfactant; a betaine surfactant; and combinations thereof; a second type of amphoteric surfactant; and a solvent.

Claims

1. A composition for use with a chrome-friendly modified acid composition for use in downhole oil industry activities, wherein the composition consists of: 10% to 80% by weight of a thiourea derivative; 5% to 75% by weight of a first amphoteric surfactant selected from the group consisting of: a sultaine surfactant, a betaine surfactant, and combinations thereof; 5% to 75% by weight of a second amphoteric surfactant; and 10% to 80% by weight of a solvent selected from the group consisting of: water, methanol, ethanol, isopropanol, and combinations thereof, wherein the composition is a liquid corrosion inhibitor composition.

2. The composition according to claim 1, wherein the thiourea derivative is 1,3 diethyl-2-thiourea.

3. The liquid corrosion inhibitor composition according to claim 1, wherein the first amphoteric surfactant is selected from the group consisting of: an amido betaine surfactant; an amido sultaine surfactant; and combinations thereof.

4. The composition according to claim 3, wherein the first amphoteric surfactant is an amido betaine comprising a hydrophobic tail from C8 to C16.

5. The composition according to claim 4, wherein the first amphoteric surfactant is cocamidopropyl betaine.

6. The composition according to claim 1, wherein the second amphoteric surfactant is beta-Alanine, N-(2-carboxyethyl)-N-dodecyl-, sodium salt (1:1).

7. The composition according to claim 1, wherein the solvent is a combination selected from the group consisting of: isopropanol-water; isopropanol-methanol; methanol-ethanol; ethanol-water; and methanol-water.

8. The composition according to claim 1, wherein the thiourea derivative is present in a concentration ranging from 15% to 50% of the weight of the composition.

9. The composition according to claim 8, wherein the thiourea derivative is present in a concentration ranging from 20% to 40% of the weight of the composition.

10. The composition according to claim 1, wherein the first amphoteric surfactant is present in a concentration ranging from 5% to 30% of the weight of the composition.

11. The composition according to claim 1, wherein the second amphoteric surfactant is present in a concentration ranging from 5% to 30% of the weight of the composition.

12. The composition according to claim 1, wherein the solvent is present in a concentration ranging from 20% to 80% of the weight of the composition.

13. The composition according to claim 12, wherein the solvent is present in a concentration ranging from 30% to 70% of the weight of the composition.

14. A modified acid composition having a pH of no more than about 1 and consisting of the composition according to claim 1 and an acid composition, said acid composition is selected from the group consisting of: HCl; HCl-urea in a molar ratio ranging from 0.1:1.0; phosphoric acid; urea-phosphoric acid in a molar ratio of not less than 0.1:1; and a phosphoric acid derivative.

15. The modified acid composition of claim 14, wherein the phosphoric acid derivative is selected from the group consisting of: polyphosphoric acid, orthophosphoric acid (H.sub.3PO.sub.4), pyrophosphoric acid (H.sub.4P.sub.2O.sub.7), tripolyphosphoric acid (H.sub.5P.sub.3O.sub.10), tetrapolyphosphoric acid (H.sub.6P.sub.4O.sub.13), trimetaphosphoric acid (H.sub.3P.sub.3O.sub.9), and phosphoric anhydride (P.sub.4O.sub.10).

16. A modified acid composition having a pH of no more than about 1 and comprising an acid selected from the group consisting of: HCl-urea in a molar ratio ranging from 0.1:1.0, phosphoric acid-urea in a molar ratio of not less than 0.1:1, and a phosphoric acid derivative; and a composition consisting of: 10% to 80% by weight of a thiourea derivative; 5% to 75% by weight of a betaine surfactant; 5% to 75% by weight of an amphoteric surfactant; and 10% to 80% by weight of a solvent.

17. A composition for use with a chrome-friendly modified acid composition for use in downhole oil industry activities, said composition consisting of: 1,3 diethyl-2-thiourea, present in a concentration ranging from 10% to 80% of the weight of the composition; a first amphoteric surfactant selected from the group consisting of: a sultaine surfactant, a betaine surfactant, and combinations thereof, present in a concentration ranging from 5% to 75% of the weight of the composition; a second amphoteric surfactant, present in a concentration ranging from 5% to 75% of the weight of the composition; and a solvent, present in a concentration ranging from 10% to 80% of the weight of the composition, wherein the composition is a composition.

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) The description that follows, and the embodiments described therein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not limitation, of those principles and of the invention.

(2) According to a preferred embodiment of the present invention, there is provided a liquid corrosion inhibitor composition for use with a chrome-friendly modified acid composition for use in downhole oil industry activities, said corrosion inhibitor composition comprising: a thiourea derivative; a first type of amphoteric surfactant is selected from the group consisting of: a sultaine surfactant; a betaine surfactant; and combinations thereof; a second type of amphoteric surfactant; and a solvent.

(3) Preferably, the thiourea derivative is 1,3 diethyl-2-thiourea. Preferably also, the sultaine surfactant and betaine surfactant are selected from the group consisting of: an amido betaine surfactant; an amido sultaine surfactant; and combinations thereof. More preferably, the amido betaine surfactant is an amido betaine comprising a hydrophobic tail from C8 to C16. More preferably, the amido betaine comprising a hydrophobic tail from C8 to C16 is cocamidopropyl betaine.

(4) According to a preferred embodiment, the second-type of amphoteric surfactant is beta.-Alanine, N-(2-carboxyethyl)-N-dodecyl-, sodium salt (1:1).

(5) Preferably, the solvent is an alcohol selected from the group consisting of: methanol, ethanol and isopropanol.

(6) According to a preferred embodiment, the thiourea derivative is present in a concentration ranging from 10 to 90% of the weight of the composition. Preferably, the thiourea derivative is present in a concentration ranging from 15 to 50% of the weight of the composition. Even more preferably, the thiourea derivative is present in a concentration ranging from 20 to 40% of the weight of the composition. Yet more preferably, the thiourea derivative is present in a concentration of approximately 30% of the weight of the composition.

(7) According to a preferred embodiment, the betaine surfactant is present in a concentration ranging from 5 to 90% of the weight of the composition. Preferably, the betaine surfactant is present in a concentration ranging from 5 to 30% of the weight of the composition.

(8) According to a preferred embodiment, the second surfactant is present in a concentration ranging from 5 to 90% of the weight of the composition. Preferably, the second surfactant is present in a concentration ranging from 5 to 30% of the weight of the composition.

(9) According to a preferred embodiment, the solvent is present in a concentration ranging from 10 to 90% of the weight of the composition. Preferably, the solvent is present in a concentration ranging from 20 to 80% of the weight of the composition. More preferably, the solvent is present in a concentration ranging from 30 to 70% of the weight of the composition. Even more preferably, the solvent is present in a concentration ranging from 40 to 60% of the weight of the composition.

(10) According to another aspect of the present invention, there is provided a corrosion inhibitor composition for use with an acid composition, said acid composition is selected from a group consisting of: HCl; HCl-urea in a molar ratio ranging from 0.1:1.0; phosphoric acid; and urea-phosphoric acid or a derivative thereof in a molar ratio of not less than 0.1:1.

(11) According to another aspect of the present invention, there is provided a modified acid composition comprising an acid selected from the group consisting of: HCl; HCl-urea; phosphoric acid-urea and a phosphoric acid derivative; and a corrosion inhibitor composition comprising: a thiourea derivative; a betaine surfactant; an amphoteric surfactant; and a solvent.

(12) Preferably, the modified acid composition of claim 20 where the phosphoric acid derivative is selected from the group consisting of: polyphosphoric acid, orthophosphoric acid (H.sub.3PO.sub.4), pyrophosphoric acid (H.sub.4P.sub.2O.sub.7), tripolyphosphoric acid (H.sub.5P.sub.3O.sub.10), tetrapolyphosphoric acid (H.sub.6P.sub.4O.sub.13), trimetaphosphoric acid (H.sub.3P.sub.3O.sub.9), and phosphoric anhydride (P.sub.4O.sub.10).

(13) According to another aspect of the present invention, there is provided a corrosion inhibitor composition for use in the oil industry to perform an operation selected form the group consisting of: stimulate formations; to assist in reducing breakdown or injection pressures during downhole pumping operations; to treat wellbore filter cake post drilling operations; to assist in freeing stuck pipe; to descale pipelines and/or production wells; to increase injectivity rate of injection wells; to lower the pH of fluids; to remove undesirable scale in surface equipment, wells and related equipment and/or facilities; to conduct annular and bullhead squeezes & soaks; to increase effective permeability of formations; to reduce or remove wellbore skin damage; to clean perforations; to solubilize limestone, dolomite, calcite and combinations thereof; and to drill out cement plugs.

(14) According to another aspect of the present invention, there is provided a liquid corrosion inhibitor composition for use with a chrome-friendly modified acid composition for use in industrial activities, said corrosion inhibitor composition comprising: a thiourea derivative; a first type of amphoteric surfactant is selected from the group consisting of: a sultaine surfactant; a betaine surfactant; and combinations thereof; a second type of amphoteric surfactant; and a solvent.

(15) According to another aspect of the present invention, there is provided a composition comprising a phosphoric acid component (as described previously herein) and a corrosion inhibitor composition comprising: a thiourea derivative; a first type of amphoteric surfactant is selected from the group consisting of: a sultaine surfactant; a betaine surfactant; and combinations thereof; a second type of amphoteric surfactant; and a solvent for use in various industrial activities including, but not limited to: metal pickling metal polishing scale removal in water treatment applications; the removal of hardened cement or cement-like materials on surfaces metal surfaces including chrome and in the most preferred embodiment other “soft” metals. Another preferred embodiment of the above composition can be employed for etching concrete (thus minimizing damage to metals close to the etching site) or to remove efflorescence build up. Other uses for the above preferred composition according include: pH control; sanitizing of food, dairy and brewery equipment; and so on, these are preferably uses where chrome or chrome plated equipment is used.

(16) When urea and a phosphoric acid derivative are used, there is a reaction that results in a urea phosphate solution with the chemical composition of CO(NH.sub.2).sub.2.Math.H.sub.3PO.sub.4, which binds the phosphate ion within the molecular structure. The low pH of urea phosphate allows Calcium, Magnesium and Phosphorus to co-exist in solution. This reaction greatly reduces the hazardous effects of the orthophosphoric acid on its own, such as the fuming effects, the hygroscopic effects, and the highly corrosive nature. When safety is sought, it is preferable to add the urea at a molar ratio greater than 1 to the moles of phosphoric acid derivative (in terms of phosphate groups). This is done in order to bind any available phosphate ions, thereby creating a safer, more stable product. Preferably, such compositions comprise 1.0 moles of urea per 1.0 moles of orthophosphoric acid. The urea also allows for a reduced rate of reaction when in the presence of carbonate-based materials. This again due to the stronger molecular or ionic bonds associated over what orthophosphoric acid traditionally displays.

(17) Some industrial activities are listed herein below: phosphoric acid is used in numerous industries such as electroplating (as an acid metal cleaners—oxide removers); in integrated iron and steel manufacturing (as pickling acid); as a standard acid in laboratory chemicals; in machinery manufacturing and repair (as a clean wash agent); in pH regulation agents (as pH adjustor for water treatment); in printed circuit board manufacturing (in making PCB holes conductive and for outer layer etch/plate); in semiconductors (for wet chemical etching); and in welding and soldering agents (as corrosive flux ingredient).

(18) Some advantages of urea-phosphoric acid compositions permit the end user to utilize an alternative to conventional acids that has transportation and storage advantages as well as health, safety and environmental advantages Enhancement in short/long term corrosion control is one of the key advantages of the present invention. The reduction in skin corrosiveness, the elimination of corrosive fumes during reactions, the controlled spending nature, and the high salt tolerance and the resistance to damaging chrome and chrome-plated metals and standard non-plated metals make the use of urea-phosphoric acid more desirable than phosphoric acid alone. However, even urea has limits on the corrosion prevention, which is why suitable corrosion inhibitor packages are still very much sought after in order to implement on a larger scale the use of phosphoric acid and derivatives thereof as well as modified acids of phosphoric acid.

(19) Chrome-friendly is understood to mean that the corrosion on a standard chrome surface upon exposure of the modified acid composition is at least 50% less than the corrosion of the same type of chrome surface at a temperature of 20° C. for a period of time of 6 hours.

(20) According to the SDS sheet of Armohib 31®, this inhibitor is said to be designed for use with phosphoric acid. It is said to contain a proprietary alkoxylated fatty amine salts (in an undisclosed % content), a proprietary alkoxylated organic acid (in an undisclosed content), and N,N′-dibutyl thiourea in an amount ranging from 20-30% by weight. This corrosion inhibitor does however not address the fuming and environmental toxicity drawbacks associated with the use of phosphoric acids, nor does it address the corrosion effect on chrome. It mainly addresses the corrosion on steel surfaces.

Example 1—Process to Prepare an Acid Composition for Use with a Corrosion Inhibitor According to a Preferred Embodiment of the Invention

(21) Start with a 50% by weight solution of urea liquor in water. Add 85% by weight solution of orthophosphoric acid and circulate until all reactions have completely ceased. Immediately add water to a desired concentration of 50%.

(22) Table 1 lists the components of the acid composition of Example 1 comprising a corrosion inhibitor according to the present invention, including their weight percentage as compared to the total weight of the composition and the CAS numbers of each component.

(23) TABLE-US-00001 TABLE 1 Formulation of Example 1 Chemical % Wt Composition CAS# Water 43.95% 7732-18-5 Urea Phosphate   56% 4861-19-2

(24) The resulting composition of Example 1 is a clear, odourless liquid having shelf-life of greater than 1 year. It has a freezing point temperature of approximately minus 30° C. and a boiling point temperature of approximately 100° C. It has a specific gravity of 1.19±0.02. It is completely soluble in water and its pH is 1. The phosphoric acid concentration of the composition of Example 1 is 17%. This is the stock solution which is used for most corrosion testing experiments set out hereinafter. This stock solution is referred to as UREA-PHOSPHORIC ACID (100%) in the corrosion tables. When diluted, for example, at 50% of the original stock solution, the composition is referred to as UREA-PHOSPHORIC ACID (50%).

(25) The composition is classified as an irritant according to the classifications for skin tests. The composition is non-fuming and has no volatile organic compounds nor does it have any BTEX levels above the drinking water quality levels. BTEX refers to the chemicals benzene, toluene, ethylbenzene and xylene. Toxicity testing was calculated using surrogate information and the LC.sub.50 was determined to be greater than 884 mg/kg.

(26) A number of corrosion inhibitor compositions were investigated for protection against corrosion. They are listed in the below Table 2.

(27) TABLE-US-00002 TABLE 2 Corrosion inhibitor compositions investigated CI-P3A CI-P4 CI-P5 CI-P6 CI-P7 1,3 Diethyl-2-thiourea Vol % 30% 30% 30%  0% 30% Cocamidopropyl betaine Vol % 30% 10%  5% 30% .beta.-Alanine, N-(2- Vol % 10% 10%  5% 10% carboxyethyl)-N- dodecyl-, sodium salt (1:1 Isopropanol Vol % 30% 50% 60% 60% 70%

(28) The corrosion inhibitors utilized in table 2 are generally composed with isopropanol, cocamidopropyl betaine, .beta.-Alanine, N-(2-carboxyethyl)-N-dodecyl-, sodium salt (1:1) and 1,3-diethyl-2-thiourea. The solvent is measured according to the formulation. The two surfactants are then added to the solvent, followed by the active ingredient. Each component is dissolved into the solvent prior to the addition of the next chemical.

(29) Preferably, the at least one amphoteric surfactant is selected from the group consisting of: a sultaine surfactant; a betaine surfactant; and combinations thereof. More preferably, the sultaine surfactant and betaine surfactant are selected from the group consisting of: an amido betaine surfactant; an amido sultaine surfactant; and combinations thereof. Yet even more preferably, the amido betaine surfactant and is selected from the group consisting of: an amido betaine comprising a hydrophobic tail from C8 to C16. Most preferably, the amido betaine comprising a hydrophobic tail from C8 to C16 is cocamidobetaine.

(30) Preferably, the solvent is selected from the group consisting: methanol; ethanol; and isopropanol. The most preferred solvent is isopropanol.

Corrosion Testing

(31) The following corrosion testing outlined in the tables below for a number of different corrosion inhibition packages according to the present invention in the presence of a synthetic or modified acid composition was carried out diluted with saline water at a temperature of up to 135° C. (different temperatures were also used—there are indicated in the title of the tables) for various exposure periods. A desirable result was one where the lb/ft2 corrosion number is at or below 0.05. More preferably, that number is at or below 0.02. The results of the corrosion tests are reported below.

(32) TABLE-US-00003 TABLE 3 Corrosion testing of various acidic compositions with various known and commercially available corrosion inhibition packages on J55 steel coupons having a density of 7.86 g/cc at 70° C. Surface Run Additional Area Time Coupon Fluid Inhibitor (cm2) (hours) Mils/yr mm/year lb/ft2 J-55 UREA-PHOSPHORIC 28.922 6 12882.5865 327.218 0.361 ACID (100%) J-55 UREA-PHOSPHORIC 0.5% CI-4A 28.922 6 13903.8581 353.158 0.390 ACID (100%) J-55 UREA-PHOSPHORIC 0.5% Armohib 28.922 6 3081.76734 78.277 0.086 ACID (100%) CI-28 ® J-55 UREA-PHOSPHORIC 0.5% Armohib 28.922 6 71.05157717 1.805 0.002 ACID (100%) CI-31 ® J-55 UREA-PHOSPHORIC 0.5% Cronox 28.922 6 9021.780333 229.153 0.253 ACID (100%) 242ES ® J-55 UREA-PHOSPHORIC 0.5% 28.922 6 6109.171374 155.173 0.171 ACID (100%) BASOCORRAM J-55 UREA-PHOSPHORIC 0.1% Armohib 28.922 4 34.51437824 0.877 0.001 ACID (100%) CI-31 J-55 UREA-PHOSPHORIC None 28.922 3 17410.41779 442.225 0.244 ACID (100%) J-55 UREA-PHOSPHORIC 0.05% Armohib 28.922 6 199.7535444 5.074 0.006 ACID (100%) CI-31 J-55 UREA-PHOSPHORIC 0.05% Armohib 28.922 24 91.09014476 2.314 0.010 ACID (100%) CI-31 J-55 UREA-PHOSPHORIC 0.05% Armohib 28.922 6 270.0465638 6.859 0.008 ACID (100%) CI-31 J-55 UREA-PHOSPHORIC 0.05% Armohib 28.922 6 143.6202699 3.648 0.004 ACID (100%) CI-31 J-55 UREA-PHOSPHORIC 0.2% CI-1A 28.922 6 18155.57436 461.152 0.509 ACID (100%) Where CI-1A: represents potassium iodide and CI-4A: represents propargyl alcohol

(33) TABLE-US-00004 TABLE 4 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc at 70° C. for a duration of 6 hours Surface Additional Area Coupon Fluid Inhibitor (cm2) Mils/yr mm/year lb/ft2 CR13 110 UREA-PHOSPHORIC 0.05% Armohib 30.3225 5.064656721 0.129 0.0001 ACID (100%) CI-31 CR13 110 UREA-PHOSPHORIC None 30.3225 7.958746276 0.202 0.0002 ACID (100%) CR13 110 42% Phosphoric acid 30.3225 9.888139313 0.251 0.0003 Chromed UREA-PHOSPHORIC None 23.42 5385.142694 136.783 0.151 1018CS ACID (100%) Chromed 42% Phosphoric acid 23.42 15050.35908 382.279 0.422 1018CS N80 UREA-PHOSPHORIC 0.05% Armohib 28.0774 416.2129708 10.572 0.011 ACID (100%) CI-31 N80 UREA-PHOSPHORIC 0.05% Armohib 28.0774 33129.10693 841.479 3.607 ACID (100%) CI-31 J55 UREA-PHOSPHORIC 0.125% CI-P3A 28.922 85.71702727 2.177 0.002 ACID (50%) J55 UREA-PHOSPHORIC 0.25% CI-P3A 28.922 88.49840573 2.248 0.002 ACID (50%) N80 UREA-PHOSPHORIC 0.125% CI-P3A 28.0774 207.3251094 5.266 0.006 ACID (50%) N80 UREA-PHOSPHORIC 0.25% CI-P3A 28.0774 115.9041126 2.944 0.003 ACID (50%) 2507 UREA-PHOSPHORIC 0.125% CI-P3A 33.497 1.309908806 0.033 0.000 ACID (50%) 2507 UREA-PHOSPHORIC 0.25% CI-P3A 33.497 1.964863209 0.050 0.000 ACID (50%) J55 UREA-PHOSPHORIC 0.125% CI-P4 28.922 84.19991174 2.139 0.002 ACID (50%) J55 UREA-PHOSPHORIC 0.125% CI-P5 28.922 75.60292375 1.920 0.002 ACID (50%) J55 UREA-PHOSPHORIC No CI 28.922 8805.844223 223.668 0.247 ACID (50%) J55 UREA-PHOSPHORIC 0.125% CI-P6 28.922 7797.973808 198.069 0.219 ACID (50%) J55 UREA-PHOSPHORIC 0.125% CI-P7 28.922 100.8881825 2.563 0.003 ACID (50%)

(34) TABLE-US-00005 TABLE 5 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc at 100° C. for a duration of 6 hours Surface Additional Area Coupon Fluid Inhibitor (cm2) Mils/yr mm/year lb/ft2 N80 UREA-PHOSPHORIC 0.05% Armohib CI-31 28.0774 1125.962874 28.599 0.031 ACID (100%) N80 UREA-PHOSPHORIC 0.1% Armohib CI-31 28.0774 180.4978653 4.585 0.005 ACID (100%)

(35) TABLE-US-00006 TABLE 6 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc for 6 hours at 70° C. Steel coupon Temp Corrosion Surface type Fluid (° C.) inhibitor area Mils/yr mm/year lb/ft2 J55 UREA-PHOSPHORIC 70 0.125% CI-P3A 28.922 85.71703 2.177 0.002 ACID (50%) J55 UREA-PHOSPHORIC 70 0.25% CI-P3A 28.922 88.49841 2.248 0.002 ACID (50%) N80 UREA-PHOSPHORIC 70 0.125% CI-P3A 28.0774 207.3251 5.266 0.006 ACID (50%) N80 UREA-PHOSPHORIC 70 0.25% CI-P3A 28.0774 115.9041 2.944 0.003 ACID (50%) 2507 UREA-PHOSPHORIC 70 0.125% CI-P3A 33.497 1.309909 0.033 0.000 ACID (50%) 2507 UREA-PHOSPHORIC 70 0.25% CI-P3A 33.497 1.964863 0.050 0.000 ACID (50%) J55 UREA-PHOSPHORIC 70 0.125% CI-P4 28.922 84.19991 2.139 0.002 ACID (50%) J55 UREA-PHOSPHORIC 70 0.125% CI-P5 28.922 75.60292 1.920 0.002 ACID (50%) J55 UREA-PHOSPHORIC 70 No CI 28.922 8805.844 223.668 0.247 ACID (50%) J55 UREA-PHOSPHORIC 70 0.125% CI-P6 28.922 7797.974 198.069 0.219 ACID (50%) J55 UREA-PHOSPHORIC 70 0.125% CI-P7 28.922 100.8882 2.563 0.003 ACID (50%) J55 17% H.sub.3PO.sub.4 70 0.125% CI-P5 28.922 112.7723 2.864 0.003 J55 17% H.sub.3PO.sub.4 70 0.125% CI-P7 28.922 91.27978 2.319 0.003 J55 H.sub.3PO.sub.4 same conc. As 70 No CI 28.922 80008.6000 203.418 0.225 50% UREA- PHOSPHORIC ACID

(36) TABLE-US-00007 TABLE 7 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc for 6 hours at various temperatures Steel coupon Temp Corrosion Surface type Fluid (° C.) inhibitor area Mils/yr mm/year lb/ft2 2507 UREA-PHOSPHORIC 120 0.125% CI-P5 33.497 −0.43664 −0.011 0.000 ACID (50%) 2507 UREA-PHOSPHORIC 120 0.125% CI-P7 33.497 0.436636 0.011 0.000 ACID (50%) J55 17% H.sub.3PO.sub.4 120 0.125% CI-P5 28.922 342.6153 8.702 0.010 J55 17% H.sub.3PO.sub.4 120 0.125% CI-P7 28.922 3397.327 86.292 0.095 2507 17% H.sub.3PO.sub.4 120 0.125% CI-P5 33.497 −1.30991 −0.033 0.000 2507 17% H.sub.3PO.sub.4 120 0.125% CI-P7 33.497 −1.52823 −0.039 0.000

(37) TABLE-US-00008 TABLE 8 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc for 6 hours at 120° C. Steel coupon Temp Corrosion Surface type Fluid (° C.) inhibitor area Mils/yr mm/year lb/ft2 J55 H.sub.3PO.sub.4 same conc. As 120 0.125% CI-P5 28.922 342.6153 8.702 0.010 50% UREA- PHOSPHORIC ACID J55 H.sub.3PO.sub.4 same conc. As 120 0.125% CI-P7 28.922 3397.327 86.292 0.095 50% UREA- PHOSPHORIC ACID 2507 H.sub.3PO.sub.4 same conc. As 120 0.125% CI-P5 33.497 −1.30991 −0.033 0.000 50% UREA- PHOSPHORIC ACID 2507 H.sub.3PO.sub.4 same conc. As 120 0.125% CI-P7 33.497 −1.52823 −0.039 0.000 50% UREA- PHOSPHORIC ACID J55 H.sub.3PO.sub.4 same conc. As 120 0.05% Armohib 28.922 4373.338 111.083 0.123 50% UREA- CI-31 PHOSPHORIC ACID J55 H.sub.3PO.sub.4 same conc. As 120 0.125% Armohib 28.922 996.7449 25.317 0.028 50% UREA- CI-31 PHOSPHORIC ACID J55 UREA-PHOSPHORIC 120 0.05% Armohib 28.922 788.3944 20.025 0.022 ACID (50%) CI-31 J55 UREA-PHOSPHORIC 120 0.125% Armohib 28.922 306.963 7.797 0.009 ACID (50%) CI-31

(38) TABLE-US-00009 TABLE 9 Corrosion testing of various acidic compositions with various corrosion inhibition packages on steel coupons having a density of 7.86 g/cc for 6 hours at 135° C. Steel coupon Temp Corrosion Surface type Fluid (° C.) inhibitor area Mils/yr mm/year lb/ft2 J55 H.sub.3PO.sub.4 same 135 0.125% Armohib 28.922 1465.028 37.212 0.041 conc, as 50% CI-31 UREA- PHOSPHORIC ACID J55 H.sub.3PO.sub.4 same 135 0.125% CI-P5 28.922 648.8197 16.480 0.018 conc, as 50% UREA- PHOSPHORIC ACID

(39) A series of experiment as conducted in order to assess various solvent combinations in the CI package. The results reported below are the ratios (mass %) with CI-IP (current CI-P5), with CI-IP/Water, and methanol. Table 10 reports the results of the require loading as well as the corrosion inhibition with a 50% urea-phosphoric acid composition including corrosion inhibitor packages using various solvent compositions).

(40) TABLE-US-00010 TABLE 10 Solvent testing as part of various corrosion inhibition packages on J55 steel coupons for 6 hours at 70° C. Ingredient CI-IP CI-IP/Water Methanol CI-B2 5.00% 3.10% 7.76% CI-M 5.00% 3.10% 7.76% CI-DT 30.00% 18.76% 46.96% Isopropanol 60.00% 37.52% — Water — 37.52% — MeOH — — 37.55% % Vol. Loadings in Example 0.0625% 0.1010% 0.0384% 1 (for same CI-DT) Corrosion in 50% Example 1 0.004 0.005 0.004 at 70° C. for 6 hours on J55 (lb/ft.sup.2) Where CI-M = Cocamidopropyl betaine and CI-B2 = .beta.-Alanine, N-(2-carboxyethyl)-N-dodecyl-, sodium salt (1:1), and DT refers to diethyl thiourea.

(41) The above results supports the use of various solvents as well as combinations thereof including but not limited to: water, methanol, ethanol and isopropanol and combinations thereof such as isopropanol-water; isopropanol-methanol; methanol-ethanol; ethanol-water and methanol-water.

(42) Table 11 highlights the various applications that the acid compositions employing a corrosion inhibitor according to a preferred embodiment of the present invention can, upon dilution thereof (said dilution may range from approximately 1 to 100% depending on the intended use) include, but are not limited to: injection/disposal treatments; soaks; acid washes; pipeline scale treatments, cement breakdowns or perforation cleaning; pH control; and de-scaling applications.

(43) TABLE-US-00011 TABLE 11 Applications for which acid compositions using the corrosion inhibition packages according to the present invention can be used as well as proposed dilution ranges Application: Suggested Dilution: Benefits: Injection/Disposal Wells 50-100% Compatible with mutual solvents and solvent blends, very cost effective. Squeezes & Soaks 33%-100% Ease of storage & handling, cost effective Bullhead compared to conventional acid stimulations. Annular Ability to leave pump equipment in wellbore. Cement Break-downs 50-100% Higher concentrations recommended due to lower temperatures, and reduced solubility of aged cement. pH Control 0.1%-5.0%  Used in a variety of applications to adjust pH level of water based systems. Liner De-Scaling, Heavy 1%-10% Continuous injection/de-scaling of slotted liners, Oil typically at very high temperatures.

(44) One advantage of the corrosion inhibitor compositions according to the present invention includes the flexibility they provide in terms of acid compositions with which they can be incorporated (or admixed). Indeed, HCl and phosphoric acids have substantially different corrosion profiles when referring to the types of metals with which they are compatible. Moreover, the corrosion inhibitor composition according to a preferred embodiment of the present invention provides protection against carbon steel metals as well as chrome or chrome-plated metals. As the oil industry uses both (and more) metals, often times within the same area of fluidic circulation it is desirable to be able to use acids which will not corrode one or the other metal, and more preferably neither.

(45) The uses (or applications) of the compositions according to the present invention upon dilution thereof ranging from approximately 1 to 90% dilution, include, but are not limited to: injection/disposal treatments; matrix acid squeezes, soaks or bullheads; acid fracturing, acid washes; fracturing spearheads (breakdowns); pipeline scale treatments, cement breakdowns or perforation cleaning; pH control; and de-scaling applications, high temperature (up to 135° C.) cyclical steam scale treatments and steam assisted gravity drainage (SAGD) scale treatments (up to 135° C.).

(46) As would be understood by the person skilled in the art, the methods of use generally comprise the following steps: providing a corrosion inhibitor composition according to a preferred embodiment of the present; admixing the corrosion inhibitor composition to an acidic composition; exposing a surface (such as a metal surface) to the aqueous acid composition; allowing the aqueous acid composition a sufficient period of time to act upon said surface; and optionally, removing the acid composition when the exposure time has been determined to be sufficient for the operation to be complete or sufficiently complete. Another method of use comprises: injecting the aqueous acid composition into a well and allowing sufficient time for the aqueous acid composition to perform its desired function, subsequently removing the acid composition from the well to stop the acid exposure. Yet another method of use comprises: exposing the aqueous acid composition to a body of fluid (typically water) requiring a decrease in the pH and allowing sufficient exposure time for the aqueous acid composition to lower the pH to the desired level.

(47) While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by those skilled in the relevant arts, once they have been made familiar with this disclosure, which various changes in form and detail can be made without departing from the true scope of the invention in the appended claims.