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CA-3040903-C - ACID EMULSIFIER TECHNOLOGY FOR CONTINUOUS MIXED EMULSIFIED ACID SYSTEMS

CA3040903CCA 3040903 CCA3040903 CCA 3040903CCA-3040903-C

Abstract

An acidizing well-bore stimulation fluid is provided. The acidizing well-bore stimulation fluid comprises an oil external emulsion of a hydrocarbon base fluid, an acidizing agent, and a surfactant. The surfactant comprises an imide compound and a hydrocarbon solvent. The imide compound is the reaction product of a hydrocarbyl-substituted acylating agent, and a nitrogen containing compound having a nitrogen atom which reacts with the hydrocarbyl-substituted acylating agent. The nitrogen containing compound comprises at least one of: (A) a compound of formula (see formula 1), wherein X is an alkylene group containing about 1 to about 4 carbon atoms, and each R is, individually, a hydrogen or a C1 to C6 hydrocarbyl group; (B) a compound of formula (see formula 2), wherein each X is, individually, a C1 to C6 hydrocarbyl group, and each R is, individually, a hydrogen or a C1 to C6 hydrocarbyl group; or (C) a mixture of (A) and (B).

Inventors

  • Kern L. Smith
  • Nicole Shimek
  • Nadia M. Mojica

Assignees

  • THE LUBRIZOL CORPORATION

Dates

Publication Date
20260505
Application Date
20170901
Priority Date
20161017

Claims (20)

  1. 26 Claims: 1. An acidizing well-bore stimulation fluid comprising an oil external emulsion of i. a hydrocarbon base fluid, ii. an acidizing agent, and iii. a surfactant comprising 1. an imide compound that is the reaction product of a. a hydrocarbyl-substituted acylating agent, and b. a nitrogen containing compound having a nitrogen atom which reacts with the hydrocarbyl-substituted acylating agent, the nitrogen containing compound comprising at least one of (A) a compound of formula , wherein X is an alkylene group containing 1 to 4 carbon atoms, and each R is, individually, a hydrogen or a C1 to C6 hydrocarbyl group; (B) a compound of formula , wherein each X is, individually, a C1 to C6 hydrocarbyl group, and each R is, individually, a hydrogen or 27 a C1 to C6 hydrocarbyl group; or (C) a mixture of (A) and (B), and 2. a hydrocarbon solvent.
  2. 2. The well-bore stimulation fluid of claim 1, wherein the acidizing agent comprises an inorganic acid, an organic acid or combinations thereof.
  3. 3. The well-bore stimulation fluid of any one of claims 1 or 2, wherein the acidizing agent comprises additives.
  4. 4. The well-bore stimulation fluid of any one of claims 1 to 3, wherein the acidizing agent comprises hydrochloric acid (HCl), hydrofluoric acid (HF), sulfamic acid, urea hydrochloride, formic acid, acetic acid, citric acid, lactic acid, glycolic acid or combinations thereof.
  5. 5. The well-bore stimulation fluid of any one of claims 1 to 4, wherein the acidizing agent is present in the acidizing well-bore stimulation fluid in an amount of about 55% to about 90% by volume based on the total volume of the well-bore stimulation fluid.
  6. 6. The well-bore stimulation fluid of any one of claims 1 to 5, wherein the hydrocarbyl substituent of the hydrocarbyl-substituted acylating agent has a number average molecular weight of from about 100 to about 5000.
  7. 7. The well-bore stimulation fluid of any one of claims 1 to 6, wherein the hydrocarbyl substituent of the hydrocarbyl-substituted acylating agent comprises a polyolefin.
  8. 8. The well-bore stimulation fluid of claim 7, wherein the polyolefin is polyisobutylene.
  9. 9. The well-bore stimulation fluid of any one of claims 1 to 8, wherein the acylating agent of the hydrocarbyl-substituted acylating agent comprises fumaric acid, itaconic acid, maleic acid, or combinations thereof.
  10. 10. The well-bore stimulation fluid of any one of claims 1 to 8, wherein the hydrocarbylsubstituted acylating agent is polyiso-butenyl succinic anhydride or polyisobutenyl succinic acid.
  11. 11. The well-bore stimulation fluid of any one of claims 1 to 10, wherein the nitrogen containing compound comprises dimethyl-aminopropylamine.
  12. 12. The well-bore stimulation fluid according to any one of claims 1 to 11, wherein the hydrocarbon base fluid comprises at least one of crude oil, diesel fuel, biodiesel, gasoline, xylene, 28 kerosene, d-limonene, naptha, solvent naptha, mineral spirits, or carbon tetrachloride.
  13. 13. The well-bore stimulation fluid according to any one of claims 1 to 12, wherein the hydrocarbon base fluid comprises an emulsifying surfactant and additional additives.
  14. 14. The well-bore stimulation fluid according to any one of claims 1 to 13, wherein the hydrocarbon solvent comprises at least one of crude oil, diesel fuel, biodiesel, gasoline, xylene, kerosene, d-limonene, naptha, solvent naptha, mineral spirits, or carbon tetrachloride.
  15. 15. The well-bore stimulation fluid according to any one of claims 1 to 14, wherein the concentration of the surfactant in the hydrocarbon base fluid is from about 0.01% by volume to about 2% by volume.
  16. 16. The well-bore stimulation fluid according to any one of claims 1 to 15, wherein the molar ratio of the imide to the hydrocarbon solvent in the surfactant is from about 1:1 to about 10:1.
  17. 17. A method of emulsifying an acidizing agent in a hydrocarbon base fluid, comprising the steps of: adding to the hydrocarbon fluid a surfactant comprising: 1. an imide compound that is the reaction product of a. a hydrocarbyl-substituted acylating agent, and b. a nitrogen containing compound having a nitrogen atom which reacts with the hydrocarbyl-substituted acylating agent, the nitrogen containing compound comprising at least one of (A) a compound of formula , wherein X is an alkylene group containing 1 to 4 carbon atoms, and each R is, individually, a hydrogen or a C1 to C6 hydrocarbyl group; (B) a compound of formula 29 , wherein each X is, individually, a C1 to C6 hydrocarbyl group, and each R is, individually, a hydrogen or a C1 to C6 hydrocarbyl group; or (C) a mixture of (A) and (B), and 2. a hydrocarbon solvent; and adding the acidizing agent to the hydrocarbon fluid.
  18. 18. The method of claim 17, further comprising the step of mixing the hydrocarbon base fluid comprising the surfactant, and the acidizing agent.
  19. 19. The method of claim 17 or claim 18, further comprising the step of mixing the hydrocarbon base fluid comprising the surfactant and the acidizing agent for less than 60 seconds.
  20. 20. The method of any one of claims 17 to 19, wherein the adding of the surfactant is completed on-the-fly.

Description

1 ACID EMULSIFIER TECHNOLOGY FOR CONTINUOUS MIXED EMULSIFIED ACID SYSTEMS BACKGROUND OF THE INVENTION [0001] In one embodiment, the present technology provides a surfactant composition comprising an imide compound in an optional solvent for use in a hydrocarbon base fluid to improve the emulsification of an acidizing agent in the hydrocarbon base fluid. In another embodiment, the present technology provides a method of employing an 10 acidizing well-bore stimulation fluid containing the surfactant composition to stimulate a reservoir. [0002] Current practice in preparing acidizing fluids for treatment of carbonate formations, with elevated downhole temperatures, is to prepare a stable emulsion of the acidizing agent utilizing a batch mix- 15 ing process. Unless a stable emulsion is created, the acidizing agent will separate out of the hydrocarbon base fluid and result in ineffective well stimulation due to poor wormhole propagation, poor etched patterns and excessive corrosion of well tubulars. The batch mixing process requires a lengthy period of mixing to ensure fluid stability at 20 downhole conditions, especially for high temperatures. Typically it takes about 3-4 hours to prepare a 500 barrel mixing tank. This batch process also commits the user to a certain acid blend that cannot be changed on the job, should the well response dictate otherwise. [0003] A need exists for a continuous, or "on-the-fly" method to 25 prepare an acidizing fluid. This will improve field operational efficiency and provide an opportunity to reduce environmental hazards associated with the batch mix process. SUMMARY OF THE INVENTION 30 [0004] The disclosed technology, therefore, solves the problem of preparing a stable acidizing fluid in a continuous process by using an imide compound as a surfactant to emulsify that acid in a hydrocarbon Date re9ue/Date received 2024-01-31 2 fluid. The composition and method disclosed herein significantly reduce mixing times, provides a simple additive, allowing for lower concentrations of the necessary chemicals, cost of special surface mixing equipment, less fluid preparation time and reduction of waste (result- 5 ing in less environmental exposure and costs). [0005] One aspect of the invention is an acidizing well-bore stimulation fluid. The fluid includes an oil external emulsion of a hydrocarbon base fluid, an acidizing agent, and a surfactant. The surfactant itself encompasses an imide compound that is the reaction product of 10 a hydrocarbyl-substituted acylating agent, and a nitrogen containing compound having a nitrogen atom capable of reacting with said hydrocarbyl- su bstituted acylating agent. The imide compound may or may not be carried in a hydrocarbon solvent. [0006] The acidizing agent used in the well-bore stimulation fluid 15 can contain, in addition to the acid or acid blend, additional additives, such as an acid corrosion inhibitor, acid corrosion intensifier, iron control agent, hydrogen sulfide scavenger, acid gelling agent, friction reducer, scale inhibitor, clay control agent and other surface active agents. 20 [0007] The acidizing agent may be an inorganic acid, an orgamc acid or combinations thereof. In some embodiments, the acidizing agent can be any one of hydrochloric acid (HCI), hydrofluoric acid (HF), sulfamic acid, urea hydrochloride, formic acid, acetic acid, citric acid, lactic acid, glycolic acid or combinations thereof. The acid can be pre- 25 sent in the acidizing well-bore stimulation fluid in an amount of about 55% to about 90% by volume based on the total volume of the wellbore stimulation fluid. [0008] The hydrocarbyl substituent of the hydrocarbyl-substituted acylating agent can have a number average molecular weight of 30 from about 100 to about 5000. The hydrocarbyl substituent of the hydrocarbyl-substituted acylating agent can be a polyolefin, such as, for example, polyisobutylene. Date re9ue/Date received 2024-01-31 3 [0009) The acylating agent of the hydrocarbyl-substituted acylating agent can be, for example, fumaric acid, itaconic acid, maleic acid, or combinations thereof. [0010] In an embodiment, the hydrocarbyl-substituted acylating 5 agent can be polyisobutenyl succinic anhydride or polyisobutenyl succinic acid. [0011] The nitrogen containing compound used to prepare the imide compound can be an aliphatic hydrocarbyl-amine. In particular embodiments, the nitrogen containing compound can be a compound 10 of formula: a compound of formula and mixtures thereof, 15 where X is an alkylene group containing from about 1 to about 4 carbon atoms and each R is, individually, a hydrogen or a Cl to C6 hydrocarbyl group. [0012] In a specific embodiment, the nitrogen containing compound can be dimethylaminopropylamine. 20 [0013] The hydrocarbon base fluid used in the well-bore stimulation fluid can contain, in addition to the emulsifying surfactant, additional additives, such as a viscosifying agent, friction reducer, paraffin inhibitor or dispersant, and