Method of treating a formation using deformable proppants

Abstract

A substance and method for treating a subterranean formation using hydraulic fracturing. A non-metallic, substantially deformable, proppant particle is “elastically flexible” or “plastically compressible” and adapted for use at concentrations which will substantially create a partial monolayer. The method for treating a formation with a non-metallic deformable proppant, includes the steps of 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 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, the deformable proppant forming substantially a partial monolayer in the fracture, and 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.

1 . A non-metallic, substantially deformable, proppant particle that is “elastically flexible” or “plastically compressible” 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 , comprising a single polymer or a combination of polymers that are layered or coated to create a particle.  
   
   
       6 . The deformable proppant of  claim 1 , comprising a solid outer shell or layers of polymer that encase an inner fluid.  
   
   
       7 . The deformable proppant of  claim 1 , having a sphericity of 0.9 to 0.3, tested in accordance with API RP 56.  
   
   
       8 . The deformable proppant of  claim 1 , having a roundness of 0.1 to 0.90, tested in accordance with API RP 56.  
   
   
       9 . The deformable proppant of  claim 1 , being crush resistant under a closure stress.  
   
   
       10 . The deformable proppant of  claim 9 , wherein the closure stress is between about 10 MPa and about 80 MPa.  
   
   
       11 . The deformable proppant of  claim 10 , wherein the closure stress is between about 20 MPa and about 50 MPa.  
   
   
       12 . The deformable proppant of  claim 1 , wherein the deformable proppant is substantially chemically inert.  
   
   
       13 . The deformable proppant of  claim 1 , wherein the deformable proppant is adapted to be substantially non-soluble in a formation fluid.  
   
   
       14 . 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.  
   
   
       15 . The deformable proppant of  claim 1 , wherein the particle has a specific gravity of between about 0.1 and about 2.5.  
   
   
       16 . The deformable proppant of  claim 15 , wherein the particle has a specific gravity of between about 0.5 and about 2.2.  
   
   
       17 . The deformable proppant of  claim 16 , wherein the particle has a specific gravity of between about 0.9 and about 2.0.  
   
   
       18 . The deformable proppant of  claim 1 , wherein the proppant has a crush resistance of more than substantially 50 MPa.  
   
   
       19 . The deformable proppant of  claim 18 , wherein the proppant has a crush resistance of more than substantially 80 MPa.  
   
   
       20 . The deformable proppant of  claim 1 , wherein the proppant is substantially non-permeable.  
   
   
       21 . The deformable proppant of  claim 1 , wherein the proppant is substantially non-absorbent of fracturing fluid.  
   
   
       22 . The deformable proppant of  claim 1 , wherein the proppant has a predeformed maximum cross sectional measurement of about 5.0 mm.  
   
   
       23 . 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).  
   
   
       24 . 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.    
   
   
       25 . The method of  claim 24 , wherein the amount selected such that the proppant is placed in the fracture in a monolayer or 1.0 layer thick.  
   
   
       26 . The method of  claim 24 , wherein the amount is between about 10 and 40 kg/m3 of carrier fluid.  
   
   
       27 . The method of  claim 24 , wherein the amount is between about 25 and 100 kg/m3 of carrier fluid.  
   
   
       28 . The method of  claim 24 , wherein the amount is less than about 200 kg/m3 of carrier fluid.  
   
   
       29 . The method of  claim 24 , wherein the portion of the deformable proppant that remains in the fracture to prop open at least a portion of the fracture is distributed at a proppant concentration, the proppant concentration in kg/m2 being less than 1.088(r)(SG), wherein r is the equivalent radius of the proppant in millimeters and SG is the specific gravity of the proppant.  
   
   
       30 . The method of  claim 24 , wherein the fracture is a generally horizontal fracture.  
   
   
       31 . The method of  claim 24 , wherein the fracture has both a generally vertical and a generally horizontal component.  
   
   
       32 . The method of  claim 24 , wherein the carrier fluid is a gas, a liquid, a foam or a combination thereof.  
   
   
       33 . The method of  claim 24 , wherein the proppant is elastically, plastically, or elastically and plastically deformed under a closure stress.  
   
   
       34 . The method of  claim 33  wherein the closure stress is between about 20 MPa and about 80 MPa.  
   
   
       35 . The method of  claim 24 , 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.  
   
   
       36 . The method of  claim 24 , wherein the proppant is deformed when a closure stress is applied.  
   
   
       37 . 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.