Solvent systems having a high flash point and methods of use thereof

Abstract

A method and composition of treating an oil or gas well having a wellbore, well casing, production equipment or recovery equipment. The method involves introducing into the wellbore, well casing, production equipment or recovery equipment a high flash point solvent blend. The blend includes at least one C 1 -C 4 ester of a C 16 -C 20 fatty acid component, at least one terpene hydrocarbon component (e.g., a pure gum turpentine, an oil of turpentine, or mixture thereof), and optionally at least one emulsifier component. The weight percent ratio of the at least one C 1 -C 4 ester of a C 16 -C 20 fatty acid component to the at least one terpene hydrocarbon component is from about 60:40 weight percent to about 95:5 weight percent, based on the total weight of the blend. The blend has a flash point greater than about 140° F. The blend may be biodegradable, and has no ozone depleting compounds, no hazardous air pollutants, and no carcinogens.

What is claimed is: 
     
         1 . A composition comprising:
 a blend of at least one C 1 -C 4  ester of a C 16 -C 20  fatty acid component, and at least one terpene hydrocarbon component;   wherein the at least one C 1 -C 4  ester of a C 16 -C 20  fatty acid component to the at least one terpene hydrocarbon component has a weight percent ratio that is from about 60:40 weight percent to about 95:5 weight percent, based on the total weight of the composition;   wherein the blend is present in an amount from about 10 to about 50 weight percent, based on the total weight of the composition; and   an acid being added in an amount so that the pH of the blend composition is about 4 or less.   
     
     
         2 . The composition of  claim 1 , further comprising an emulsifier component. 
     
     
         3 . The composition of  claim 1 , wherein the composition has a flash point greater than about 140° F. 
     
     
         4 . The composition of  claim 2 , wherein the composition forms a microemulsion upon mixing with water. 
     
     
         5 . The composition of  claim 1 , wherein the acid is selected from the group consisting of phosphoric acid, hydrochloric acid, sulfuric acid, and nitric acid. 
     
     
         6 . The composition of  claim 1 , wherein the at least one C 1 -C 4  ester of a C 16 -C 20  fatty acid component comprises corn, mustard, niger seed, olive, peanut, poppy seed, rapeseed, safflower, sesame, soybean, sunflower seed, wheat germ, or mixtures thereof. 
     
     
         7 . The composition of  claim 1 , wherein the at least one C 1 -C 4  ester of a C 16 -C 20  fatty acid component comprises a C 16 -C 20  fatty acid methyl ester, or a soybean methyl ester. 
     
     
         8 . The composition of  claim 1 , wherein the at least one terpene hydrocarbon component comprises a pure gum turpentine, an oil of turpentine, or mixture thereof. 
     
     
         9 . The composition of  claim 1 , wherein the at least one terpene hydrocarbon component comprises terpinolene, alpha-ocimene, beta-ocimene, alpha-terpinene, beta-terpinene, gamma-terpinene, sabinene, alpha-thujene, beta-thujene, camphene, carene, pinene, or mixture thereof. 
     
     
         10 . The composition of  claim 1 , wherein the at least one terpene hydrocarbon component further comprises at least one terpenoid component. 
     
     
         11 . The composition of  claim 2 , wherein the emulsifier component is anionic, nonionic, amphoteric, or mixtures thereof. 
     
     
         12 . The composition of  claim 2 , wherein the emulsifier component is selected from the group consisting of polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, linear alcohol alkoxylates, alkyl ether sulfates, linear nonyl-phenols, dioxane, ethylene glycol and ethoxylated castor oils such as polyethylene glycol castor oil, dipalmitoylphosphatidylcholine (DPPC), polyoxyethylene (8.6) nonyl phenyl ether, ethylene oxide sulfonates, alkyl propoxy-ethoxysulfate, alkylarylpropoxy-ethoxysulfonate, and highly substituted benzene sulfonates. 
     
     
         13 . The composition of  claim 2 , wherein the emulsifier component is a linear polyoxyethylene alcohol having from about 13 to about 15 carbon atoms and comprising about 8 to about 12 moles ethylene oxide. 
     
     
         14 . The composition of  claim 1 , wherein the blend further comprises a surfactant. 
     
     
         15 . The composition of  claim 14 , wherein the surfactant is selected from the group consisting of an ethoxylated plant oil based surfactant, a fatty alcohol ethoxylate, a fatty acid ethoxylate, a fatty acid amide ethoxylate, a fatty acid ester, a fatty acid methyl ester ethoxylate, an alkyl polyglucoside, a polyalcohol ethoxylate, a sorbitan ester, a soy alkyltrimethyl ammonium chloride, an ethoxylated coco fatty acid, an ethoxylated coco fatty ester, an ethoxylated cocoamide, an ethoxylated castor oil, and combinations thereof. 
     
     
         16 . The composition of  claim 1 , wherein the weight percent ratio of the at least one C 1 -C 4  ester of a C 16 -C 20  fatty acid component to the at least one terpene hydrocarbon component is from about 60:40 weight percent to about 90:10 weight percent, based on the total weight of the blend. 
     
     
         17 . The composition of  claim 2 , wherein the emulsifier is present in the blend in an amount from about 0.01 to about 10 percent by weight, based on the total weight of the blend. 
     
     
         18 . The composition of  claim 14 , wherein the surfactant is present in the blend in an amount from about 0.01 to about 10 percent by weight, based on the total weight of the blend. 
     
     
         19 . The composition of  claim 2 , wherein the composition forms a microemulsion upon mixing with water. 
     
     
         20 . The composition of  claim 1 , further comprising a proppant.