Frac Fluids for Far Field Diversion

Abstract

Aqueous well treatment fluids are provided especially for use in far field diversion in low viscosity carrier fluids. The fluids comprise water, a friction reducer, and a diverter. The diverter comprises dissolvable particulates and proppants. The dissolvable particulates have a specific gravity of from about 0.9 to about 1.6 and a particle size of about 50 mesh or less. The proppants have a specific gravity of from about 0.9 to about 1.4 and a particle size of from about 20 to about 100 mesh. The dissolvable particulates have a higher specific gravity and a smaller particle size than the proppant.

What is claimed is: 
     
         1 . An aqueous well treatment fluid, said well treatment fluid comprising:
 (a) water;   (b) a friction reducer;   (c) a diverter, said diverter comprising:
 i) dissolvable particulates having:
 (1) a specific gravity of from about 0.9 to about 1.6; and 
 (2) a particle size of about 50 mesh or less; and 
 
 ii) proppants having:
 (1) a specific gravity of from about 0.9 to about 1.4; and 
 (2) a particle size of from about 20 to about 100 mesh; and 
 
 iii) wherein said dissolvable particulates have a higher specific gravity and a smaller particle size than said proppant. 
   
     
     
         2 . The fluid of  claim 1 , where the ratio of said specific gravity of said dissolvable particulates to said specific gravity of said proppant is from about 1 to about 1.6. 
     
     
         3 . The fluid of  claim 1 , where the ratio of said specific gravity of said dissolvable particulates to said specific gravity of said proppant is from about 1 to about 1.3. 
     
     
         4 . The fluid of  claim 1 , wherein said fluid has a viscosity of about 12 cps or less. 
     
     
         5 . The fluid of  claim 1 , wherein said fluid has a viscosity of about 8 cps or less. 
     
     
         6 . The fluid of  claim 1 , wherein the ratio of the maximum particle size of said proppant to that of said dissolvable particulates is from about 1.5 to about 8. 
     
     
         7 . The fluid of  claim 1 , wherein the ratio of the maximum particle size of said proppant to that of said dissolvable particulates is from about 2 to about 6. 
     
     
         8 . The fluid of  claim 1 , wherein said dissolvable particulates have a specific gravity of from about 1 to about 1.4 and a particle size of about 100 mesh or less. 
     
     
         9 . The fluid of  claim 1 , wherein said dissolvable particulates have a specific gravity of from about 1.2 to about 1.3 and a particle size of about 100 mesh or less. 
     
     
         10 . The fluid of  claim 1 , wherein said dissolvable particulates are composed of polylactic acid. 
     
     
         11 . The fluid of  claim 1 , wherein said proppant particulates have a specific gravity of from about 1 to about 1.1 and a particle size of from about 30 mesh to about 80 mesh. 
     
     
         12 . The fluid of  claim 1 , wherein said proppants are thermoset polymer beads having nanofillers. 
     
     
         13 . The fluid of  claim 1 , wherein the loading of said diverter is from about 0.1 to about 10 ppa. 
     
     
         14 . The fluid of  claim 1 , wherein the loading of said diverter is from about 0.2 to about 5 ppa. 
     
     
         15 . The fluid of  claim 1 , wherein the loading of said diverter is from about 0.5 to about 2 ppa. 
     
     
         16 . The fluid of  claim 1 , wherein the ratio of said dissolvable particulates to said proppants by weight is from about 80:20 to about 20:80. 
     
     
         17 . The fluid of  claim 1 , wherein the ratio of said dissolvable particulates to said proppants by weight is from about 60:40 to about 40:60. 
     
     
         18 . The fluid of  claim 1 , wherein said friction reducer is selected from the group consisting of polyacrylamides and derivatives, copolymers, and mixtures thereof. 
     
     
         19 . The fluid of  claim 1 , wherein said fluid comprises a surfactant. 
     
     
         20 . A method of fracturing a subterranean formation in a well, said method comprising:
 (a) providing an aqueous carrier fluid;   (b) adding a diverter to said carrier fluid, said diverter comprising:
 i) dissolvable particulates having:
 (1) a specific gravity of from about 0.9 to about 1.6; and 
 (2) a particle size of about 50 mesh or less; and 
 
 ii) proppants having:
 (1) a specific gravity of from about 0.9 to about 1.4; and 
 (2) a particle size of from about 20 mesh to about 100 mesh; and 
 
 iii) wherein said dissolvable particulates have a higher specific gravity and a smaller particle size than said proppant; and 
   (c) pumping said carrier fluid with said diverter into said formation.