Fracturing fluid composition and method of using same in geological formations

Abstract

A composition and method required for providing a fracturing fluid pumped down a well bore and into a subterranean formation under conditions of pressure that will fracture the subterranean formation is described. More specifically, the composition increases the recovery of hydrocarbons from a geological formation penetrated by a well bore, wherein the composition includes a fracturing fluid that is liquid carbon dioxide (LCO 2 ) with proppant to aid transport of the proppant in suspension, and thereby create a fracture using a fracturing fluid which is the thickened composition containing fumed silica. When the composition is without a proppant, the viscosity of the composition is increased in order to improve the fracturing operation through aspects such as increased fracture width and reduced fluid leak-off

What is claimed is: 
     
         1 . A method for increasing the production/recovery of hydrocarbons in a geological formation, comprising:
 providing a non-polar liquid carbon dioxide (LCO 2 ) from a bulk storage vessel to one or more high pressure fracture pumps;   adding a fumed silica thickener to the non-polar liquid carbon dioxide upstream of said fracture pumps and increasing the viscosity to a range of about 0.5 to 500 centipoise to form a fracturing fluid; and   pumping the fracturing fluid into the subterranean formation and placing the proppant in the fissures within the formation.   
     
     
         2 . The method of  claim 1 , further comprising metering a proppant into fracturing fluid, wherein the proppant is suspended therein. 
     
     
         3 . The method of  claim 1 , wherein 0.25 to 3 weight percent of fumed silica is added to non-polar LCO 2 . 
     
     
         4 . The method of  claim 1 , wherein the fumed silica has a surface area from about 50 to 400 m 2 /gram and an average primary particle size between 7 and 40 nanometers. 
     
     
         5 . The method of  claim 1 , wherein pumping of said fracturing fluid into the subterranean formation is at a pressure ranging from about 1,000 to 10,000 psig. 
     
     
         6 . The method of  claim 2 , wherein said proppant loaded into the LCO 2  is in the range of about 0.25 to 10 lbs/gallon of CO 2 .