Proppant pillar placement in a fracture with high solid content fluid

Abstract

A method of placing particulate blend into a fracture formed in a subterranean formation from a wellbore comprises injecting through the wellbore a first treatment fluid to initiate or propagate the fracture in the subterranean formation; wherein the first treatment fluid comprises a particulate blend slurry; the particulate blend comprising at least a first amount of particulates having a first average particle size between about 100 and 5000 micrometers and at least a second amount of particulates having a second average particle size between about three and twenty times smaller than the first average particle size; injecting through the wellbore a second treatment fluid having a viscosity different from the first treatment fluid; and forming with the particulate blend slurry a plurality of particulate-rich clusters spaced apart by particulate-free regions forming open channels.

1 . A method of placing particulate blend into a fracture formed in a subterranean formation from a wellbore, the method comprising:
 injecting through the wellbore a first treatment fluid to initiate or propagate the fracture in the subterranean formation; wherein the first treatment fluid comprises a particulate blend slurry; the particulate blend comprising at least a first amount of particulates having a first average particle size between about 100 and 5000 micrometers and at least a second amount of particulates having a second average particle size between about three and twenty times smaller than the first average particle size;   injecting through the wellbore a second treatment fluid having a viscosity different from the first treatment fluid; and   forming with the particulate blend slurry a plurality of particulate-rich clusters spaced apart by particulate-free regions forming open channels.   
     
     
         2 . The method of  claim 1 , wherein the particulate blend slurry is made of proppant and forming with the particulate blend slurry a plurality of proppant-rich clusters spaced apart by proppant-free regions forming open channels. 
     
     
         3 . The method of  claim 1 , wherein the second treatment fluid is substantially free of macroscopic particles. 
     
     
         4 . The method of  claim 1 , wherein injection of the first treatment fluid is done by alternating stages of proppant-rich phase made of the particulate blend high solid content slurry and a proppant-free phase. 
     
     
         5 . The method of  claim 4 , wherein the stages of proppant-rich phase made of the particulate blend high solid content slurry and a proppant-free phase are separated by injection of a fiber spacer. 
     
     
         6 . The method of  claim 2 , wherein the first treatment fluid comprises further a channelant, and the second treatment fluid forms a plurality of proppant clusters forming pillars spaced apart by the channelant. 
     
     
         7 . The method of  claim 6 , further comprising removing the channelant to form further open channels around the pillars for fluid flow from the subterranean formation through the fracture toward the wellbore. 
     
     
         8 . The method of  claim 1 , wherein the first treatment fluid comprises a first carrier fluid comprising a viscosifying agent or a friction reducer and water. 
     
     
         9 . The method of  claim 1 , wherein the first treatment fluid comprises a viscosifier material or a trigger and the second treatment fluid comprises respectively the trigger or the viscosifier material, wherein the viscosifer material is inactive in a first state and is able to decrease viscosity when in a second state activated by the trigger. 
     
     
         10 . The method of  claim 1 , wherein the first treatment fluid comprises a viscosifier material or a trigger and the second treatment fluid comprises respectively the trigger or the viscosifier material, wherein the viscosifer material is inactive in a first state and is able to increase viscosity when in a second state activated by the trigger. 
     
     
         11 . The method of  claim 10 , wherein the viscosifier material is a crosslinkable polymer; and wherein the trigger is a crosslinker for the crosslinkable polymer. 
     
     
         12 . The method of  claim 10 , wherein the viscosifier material is a crosslinkable polymer and a crosslinker; and wherein the trigger is a pH agent. 
     
     
         13 . The method of  claim 10 , wherein the viscosifier material is a viscoelastic surfactant and acid; and wherein the trigger is a pH agent neutralizing the acid. 
     
     
         14 . The method of  claim 1 , wherein the second treatment fluid comprises a second carrier fluid comprising a viscosifying agent or a friction reducer and water. 
     
     
         15 . The method of  claim 1 , wherein the second treatment fluid comprises a gas. 
     
     
         16 . The method of  claim 15 , wherein said gas component comprises a gas selected from the group consisting of carbon dioxide, supercritical carbon dioxide, nitrogen, air and any mixtures thereof. 
     
     
         17 . The method of  claim 15 , wherein said gas component comprises from about 10% to about 90% of total first fluid volume percent, preferably from about 30% to about 80% of total first fluid volume percent, and more preferably from about 40% to about 70% of total first fluid volume percent. 
     
     
         18 . The method of  claim 1 , wherein the particulate blend comprises a degradable material. 
     
     
         19 . The method of  claim 1 , wherein the particulate blend comprises a binding agent. 
     
     
         20 . The method of  claim 19 , wherein the binding agent is selected from the group consisting of resin, cement, sticky fiber, polymer that exhibit sticky properties at high temperature and any mixtures thereof. 
     
     
         21 . The method of  claim 1 , wherein the particulate blend comprises fiber. 
     
     
         22 . The method of  claim 21 , wherein the fibers are selected from the group consisting of glass, ceramics, carbon and carbon-based compounds, metals and metallic alloys, polylactic acid, polyglycolic acid, polyethylene terephthalate, polyol and combinations thereof. 
     
     
         23 . The method of  claim 1 , wherein the second treatment fluid has a viscosity in the range of two to ten times lower than the first treatment fluid. 
     
     
         24 . The method of  claim 1 , wherein the second treatment fluid has a viscosity in the range of two to ten times greater than the first treatment fluid. 
     
     
         25 . The method of  claim 1 , further comprising producing fluids from the subterranean formation through the open channels and the wellbore. 
     
     
         26 . A method of placing a proppant pack into a fracture formed in a subterranean formation, the method comprising:
 injecting through the wellbore a first treatment fluid to initiate or propagate the fracture in the subterranean formation; wherein the first treatment fluid comprises a particulate blend slurry made of proppant; the particulate blend comprising at least a first amount of particulates having a first average particle size between about 100 and 5000 micrometers and at least a second amount of particulates having a second average particle size between about three and twenty times smaller than the first average particle size;   injecting through the wellbore a second treatment fluid having a viscosity different from the first treatment fluid; and   forming with the particulate blend slurry a plurality of proppant-rich clusters spaced apart by proppant-free regions forming open channels.   
     
     
         27 . The method of  claim 26 , wherein the first treatment fluid comprises a viscosifier material or a trigger and the second treatment fluid comprises respectively the trigger or the viscosifier material, wherein the viscosifer material is inactive in a first state and is able to decrease viscosity when in a second state activated by the trigger. 
     
     
         28 . The method of  claim 26 , wherein the first treatment fluid comprises a viscosifier material or a trigger and the second treatment fluid comprises respectively the trigger or the viscosifier material, wherein the viscosifer material is inactive in a first state and is able to increase viscosity when in a second state activated by the trigger. 
     
     
         29 . The method of  claim 28 , wherein the viscosifier material is a crosslinkable polymer; and wherein the trigger is a crosslinker for the crosslinkable polymer. 
     
     
         30 . The method of  claim 28 , wherein the viscosifier material is a crosslinkable polymer and a crosslinker; and wherein the trigger is a pH agent. 
     
     
         31 . The method of  claim 28 , wherein the viscosifier material is a viscoelastic surfactant and acid; and wherein the trigger is a pH agent neutralizing the acid. 
     
     
         32 . A method of placing a proppant pack into a fracture formed in a subterranean formation, the method comprising:
 injecting through the wellbore a first treatment fluid to initiate or propagate the fracture in the subterranean formation; wherein the first treatment fluid comprises a particulate blend slurry made of proppant; the particulate blend comprising at least a first amount of particulates having a first average particle size between about 100 and 5000 micrometers and at least a second amount of particulates having a second average particle size between about three and twenty times smaller than the first average particle size; such that a packed volume fraction of the particulate blend exceeds 0.74;   injecting through the wellbore a second treatment fluid substantially free of macroscopic particles and having a viscosity different from the first treatment fluid; and   forming with the particulate blend slurry a plurality of proppant-rich clusters spaced apart by proppant-free regions forming open channels.