Method of Treating a Formation Using Deformable Proppants

Abstract

A substance and method for treating a subterranean formation using hydraulic fracturing is provided. The method includes treating a formation with a non-metallic deformable proppant that may be substantially deformable, “elastically flexible”, or “plastically compressible.” The method may include the steps of injecting a carrier fluid into the formation at a pressure and a flow rate sufficient to create or open an existing fracture or fracture network in the formation, and placing at least a portion of the deformable proppant in the fracture by way of the carrier fluid so that the deformable proppant forms substantially a partial monolayer in the fracture, and reducing the pressure and/or the flow rate sufficiently to allow the fracture in the formation to at least partially close, wherein at least a portion of the deformable proppant remains in the fracture to prop open at least a portion of the fracture.

1 . A non-metallic, deformable, proppant particle that is elastically flexible or plastically compressible and adapted for use as a propping agent in subsurface formation fracturing operations at concentrations which will substantially create a partial monolayer. 
     
     
         2 . The deformable proppant of  claim 1 , comprising an organic, inorganic, or combination polymer. 
     
     
         3 . The deformable proppant of  claim 2 , where the polymer is manmade or naturally occurring. 
     
     
         4 . The deformable proppant of  claim 1 , comprising a single polymer or a mixture of polymers to create the particle. 
     
     
         5 . The deformable proppant of  claim 1 , having a sphericity of 0.9 to 0.3, tested in accordance with API RP 56. 
     
     
         6 . The deformable proppant of  claim 1 , having a roundness of 0.1 to 0.90, tested in accordance with API RP 56. 
     
     
         7 . The deformable proppant of  claim 1 , being crush resistant under a closure stress. 
     
     
         8 . The deformable proppant of  claim 7 , wherein the closure stress is between about 10 MPa and about 80 MPa. 
     
     
         9 . The deformable proppant of  claim 8 , wherein the closure stress is between about 20 MPa and about 50 MPa. 
     
     
         10 . The deformable proppant of  claim 1 , wherein the deformable proppant is substantially chemically inert. 
     
     
         11 . The deformable proppant of  claim 1 , wherein the deformable proppant is adapted to be substantially non-soluble in a formation fluid. 
     
     
         12 . The deformable proppant of  claim 1 , wherein the proppant comprises a material selected from the group of high density polyethylene (HDPE), polyethylene terephthalate (PET), polypropylene (PP), or styrene-divinyl-benzene copolymer. 
     
     
         13 . The deformable proppant of  claim 1 , wherein the particle has a specific gravity of between about 0.1 and about 2.5. 
     
     
         14 . The deformable proppant of  claim 13 , wherein the particle has a specific gravity of between about 0.5 and about 2.2. 
     
     
         15 . The deformable proppant of  claim 14 , wherein the particle has a specific gravity of between about 0.9 and about 2.0. 
     
     
         16 . The deformable proppant of  claim 1 , wherein the proppant has a crush resistance of more than about 50 MPa. 
     
     
         17 . The deformable proppant of  claim 16 , wherein the proppant has a crush resistance of more than about 80 MPa. 
     
     
         18 . The deformable proppant of  claim 1 , wherein the proppant is substantially non-permeable. 
     
     
         19 . The deformable proppant of  claim 1 , wherein the proppant is substantially non-absorbent of fracturing fluid. 
     
     
         20 . The deformable proppant of  claim 1 , wherein the proppant has a predeformed maximum cross sectional measurement of about 5.0 mm. 
     
     
         21 . The deformable proppant of  claim 1 , wherein the proppant is formed to have a pre-deformed initial shape, the initial shape comprising a disk, rice-shape, cubeoid, spheroid, or toroid (donut). 
     
     
         22 . A method of treating a subterranean formation with a non-metallic deformable proppant, comprising the steps of
 a. injecting a carrier fluid into the formation, the carrier fluid carrying an amount of the deformable proppant, wherein the carrier fluid is injected at a pressure and a flow rate sufficient to open a fracture (creating a new fracture or opening an existing fracture) in the formation;   b. placing at least a portion of the deformable proppant in the fracture, the deformable proppant forming substantially a partial monolayer in the fracture; and   c. reducing the pressure and/or the flow rate sufficient to allow the fracture in the formation to at least partially close,   wherein at least a portion of the deformable proppant remains in the fracture to prop open at least a portion of the fracture.   
     
     
         23 . The method of  claim 22 , wherein the amount selected such that the proppant is placed in the fracture in a monolayer or 1.0 layer thick. 
     
     
         24 . The method of  claim 22 , wherein the amount is between about 10 and 40 kg/m3 of carrier fluid. 
     
     
         25 . The method of  claim 22 , wherein the amount is between about 25 and 100 kg/m3 of carrier fluid. 
     
     
         26 . The method of  claim 22 , wherein the amount is less than about 200 kg/m3 of carrier fluid. 
     
     
         27 . The method of  claim 22 , wherein the fracture is a generally horizontal fracture. 
     
     
         28 . The method of  claim 22 , wherein the fracture has both a generally vertical and a generally horizontal component. 
     
     
         29 . The method of  claim 22 , wherein the carrier fluid is a gas, a liquid, a foam or a combination thereof. 
     
     
         30 . The method of  claim 22 , wherein the proppant is elastically, plastically, or elastically and plastically deformed under a closure stress. 
     
     
         31 . The method of  claim 30  wherein the closure stress is between about 20 MPa and about 80 MPa. 
     
     
         32 . The method of  claim 22 , wherein the proppant has an elastic deformation resistance and a plastic deformation resistance, and the closure stress is greater than the elastic deformation resistance and the closure stress is less than the plastic deformation resistance. 
     
     
         33 . The method of  claim 22 , wherein the proppant is deformed when a closure stress is applied. 
     
     
         34 . A method of treating a formation with a non-metallic deformable proppant, comprising the steps of:
 a. applying a treatment cycle comprising the steps of:
 i. injecting a carrier fluid into the formation, the carrier fluid carrying an amount of the deformable proppant, wherein the carrier fluid is injected at a pressure and a flow rate sufficient to open a fracture in the formation; 
 ii. placing at least a portion of the deformable proppant in the fracture, the deformable proppant forming substantially a partial monolayer in the fracture; and 
 iii. reducing the pressure and/or the flow rate sufficient to allow the fracture in the formation to at least partially close, wherein at least a portion of the deformable proppant remains in the fracture to prop open at least a portion of the fracture; and 
   b. repeating the treatment cycle at least one time.