Cleaning compositions for oil and gas wells, lines, casings, formations and equipment and methods of use

Abstract

The use of high flash point, low vapor pressure compositions for injection into, and coating of, gas and oil wells and surrounding underground hydrocarbon bearing formations and processing equipment for the purpose of removing scale, paraffins, tars, and other viscous constituents. Treatment results in increased flow of gas and/or oil and decreased adhesion of soil and scale in all aspects of oil and gas recovery, including hydrocarbon bearing formations, casings, lines and pumping equipment. The composition contains about 40 to 99 wt. % of a fatty acid alkyl ester blend and about 1 to 25 wt. % of at least one lower alkyl glycol ether.

What is claimed:  
     
         1 . A composition for removing and preventing build-up of parrafin, tars, heavy oil, calcium carbonate, iron oxide and other soils and scales, from gas or oil wells, hydrocarbon bearing formations, or recovery, pumping, storage, or transmission equipment, comprising about 40 to 99 wt % of a fatty acid alkyl ester blend and about 1 to 25 wt % of at least one lower alkyl glycol ether wherein the fatty acid alkyl ester blend contains C 1 -C 4  esters of C 4 -C 22  fatty acids.  
     
     
         2 . A composition according to  claim 1  wherein the fatty acid alkyl ester blend contains esters selected from the group consisting of C 1  to C 8  esters of C 4  to C 22  fatty acids.  
     
     
         3 . A composition according to  claim 2  wherein the fatty acid alkyl ester blend contains esters selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, and n-butyl esters of C 4  to C 22  fatty acids.  
     
     
         4 . A composition according to  claim 3  wherein the fatty acid alkyl ester blend contains esters selected from the group consisting of the methyl esters of C 4  to C 22  fatty acid.  
     
     
         5 . A composition according to  claim 1  wherein the lower alkyl glycol ether is selected from the group consisting of ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, and mixtures thereof.  
     
     
         6 . A composition according to  claim 1  wherein the composition further comprises 1 to 40 wt % of polyoxyalkylene glycol ethers wherein the polyoxyalkylene glycol ether has the formula:  
       R—O(C 2 H 4 O) x H or R—O—(C 3 H 6 O) n H  
       Wherein R is C 1  to C 8  alkyl and x is greater than 4.  
     
     
         7 . A composition according to  claim 6  wherein R is methyl, ethyl, propyl, or butyl.  
     
     
         8 . A composition according to  claim 7  wherein the polyoxyalkylene glycol ether is n-butoxy polyalkylene glycol ether.  
     
     
         9 . A composition according to  claim 1  wherein the composition further comprises up to 20 wt % of at least one additive selected from the group consisting of terpenes, terpene alcohols, C 8 -C 14  alcohol acetate ester blends, glycols, diacid esters, and petroleum hydrocarbons.  
     
     
         10 . A composition according to  claim 1  further comprising up to 10 wt % of a surfactant.  
     
     
         11 . A composition according to  claim 10  wherein the surfactant is selected from the group of ethoxylated nonyiphenols, linear alcohol ethoxylates, and alkanolamine salts of dodecylbenzene sulfonic acid.  
     
     
         12 . A composition according to  claim 1  wherein the fatty acid alkyl ester blend is present in amounts of about 50 to 95 wt %.  
     
     
         13 . A composition according to  claim 1  wherein the composition further comprises at least 1 wt % of an antioxidant.