Environmentally friendly base fluids and methods for making and using same

Abstract

Non-toxic, biodegradable base fluids are disclosed for use in making downhole fluids, where the base fluids include blends of paraffins, olefins, naphthenes, esters, and oxygenates, having low viscosities, having a pale-yellow color, having a flashpoint of >80° C. (175° F.) and have a pour point of about 19° F. Methods for making and using fluids include the base fluids of this invention are also disclosed

We claim: 
     
         1 . A method for using a downhole fluid comprising the step:
 drilling an oil or gas well, fracturing a formation, completing an oil or gas well, stimulating an oil or gas well, producing an oil or gas well, or lifting fluid from an oil or gas well using a downhole fluid comprising:
 a base fluid comprising a blend of biodegradable, non-toxic, non-hazardous solvents including biodegradable isoparaffins, terpenes, or mixtures and combinations thereof, and 
 a drilling, fracturing, completing, stimulating, producing, or lifting additive package, 
   where the base fluid has a low viscosity, has a flashpoint of >80° C. (175° F.), has a pour point of about 19 ° F. (−7.2° C.), is non-toxic, is biodegradable, and has an operating temperature range up to about 450° F.   
     
     
         2 . The method of  claim 1 , wherein the drilling, completing, producing or lifting additive package comprises at least a foaming agent and a gas in concentrations sufficient to produce a foamed drilling fluid having a foam height of at least 150 mL and a half life of at least 2 minutes. 
     
     
         3 . The method of  claim 2 , wherein the base fluid comprises blends of isoparaffins and terpenes. 
     
     
         4 . The method of  claim 3 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         5 . The method of  claim 2 , wherein the base fluid comprises blends of isoparaffins and mixtures of terpenes. 
     
     
         6 . The method of  claim 5 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         7 . The composition of  claim 2 , wherein the base fluid comprises blends of isoparaffins. 
     
     
         8 . The composition of  claim 1 , wherein the completing, stimulating, producing, or lifting additive package include polymers and gelling agents, where the gelled compositions have increased viscosity. 
     
     
         9 . A method for drilling comprising the step:
 drilling an oil or gas well with a drilling fluid comprising:
 a base fluid comprising a blend of biodegradable, non-toxic, non-hazardous solvents including biodegradable isoparaffins, terpenes, or mixtures and combinations thereof, and 
 a drilling fluid additive package comprising at least a foaming agent and a gas in concentrations sufficient to produce a foamed downhole fluid having a foam height of at least 150 mL and a half life of at least 2 minutes, 
 where the additive package comprises at least a foaming agent and a gas in concentrations sufficient to produce a foamed drilling fluid having a foam height of at least 150 mL and a half life of at least 2 minutes, and 
   where the base fluid has a low viscosity, has a flashpoint of >80° C. (175° F.), has a pour point of about 19° F. (−7.2° C.), is non-toxic, is biodegradable, and has an operating temperature range up to about 450° F.   
     
     
         10 . The method of  claim 9 , wherein the base fluid comprises blends of isoparaffins and terpenes. 
     
     
         11 . The method of  claim 10 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         12 . The method of  claim 10 , wherein the base fluid comprises blends of isoparaffins and mixtures of terpenes. 
     
     
         13 . The method of  claim 12 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         14 . The composition of  claim 10 , wherein the base fluid comprises blends of isoparaffins. 
     
     
         15 . A method for fracturing comprising the step:
 fracturing an oil or gas well with a fracturing slurry comprising:
 the base fluid, and 
 a fracturing fluid additive package comprising at least a clay, a surfactant blend, a polymer, and a winterizing agent, 
   where the base fluid has a low viscosity, has a flashpoint of >80° C. (175° F.), has a pour point of about 19° F. (−7.2° C.), is non-toxic, is biodegradable, and has an operating temperature range up to about 450° F.   
     
     
         16 . The method of  claim 15 , wherein the fracturing slurry further includes a foaming agent and a gas in concentrations sufficient to produce a foamed drilling fluid having a foam height of at least 150 mL and a half life of at least 2 minutes. 
     
     
         17 . The method of  claim 15 , wherein the base fluid comprises blends of isoparaffins and terpenes. 
     
     
         18 . The method of  claim 17 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         19 . The method of  claim 17 , wherein the base fluid comprises blends of isoparaffins and mixtures of terpenes. 
     
     
         20 . The method of  claim 19 , wherein the terpenes comprise d-limonenes, orange terpenes, lemon terpenes, grapefruit terpenes, orange oil, lemon oil, other citrus terpenes, other citrus oils, or mixtures and combinations thereof. 
     
     
         21 . The composition of  claim 17 , wherein the base fluid comprises blends of isoparaffins.