Proppant and production method thereof

Abstract

The invention relates to the oil-and-gas production industry and can be used for enhancement of the production of oilfield wells as it prevents the fracture from closing by pumping of propping granules (proppant) during the hydraulic fracturing of oil-producing formations. Higher stimulation of a reservoir through using hydraulic fracturing is provided with the proppant as particulate with spherical or elliptic form, made of ceramic, polymer, metal, or glass and having higher roughness than regular proppant, wherein the surface roughness is nonuniform and described by two criteria A and B, varying in the intervals: A =0.0085−0.85; B=0.001−1.0. The proppant manufacturing method comprising the preparation of raw material, mixing, granulation, drying, firing, wherein an additional stage of creation of surface roughness is added at the granulation stage and/or the firing stage.

1 - 13 . (canceled) 
     
     
         14 . A method comprising:
 (a) providing a proppant with a rough surface;   (b) delivering the proppant to a fracture created in a subterranean formation by hydrofracturing operation;   (c) flowing back fluids delivered to the subterranean formation during the hydrofracturing operation;   whereby at least a significant prevention of flowback of the proppant is realized during (c), while maintaining high proppant pack permeability.   
     
     
         15 . The method of  claim 14  wherein the proppant comprises a particulate with spherical or elliptic form, made of ceramic, polymer, metal, or glass and having higher roughness than regular proppant, wherein the surface roughness is nonuniform and described by two criteria A and B, varying in the intervals: A=0.0085−0.85; B=0.001−1.0. 
     
     
         16 . The method of  claim 14  further comprising manufacturing the proppant by preparation of raw material, mixing, granulation, drying, firing, and wherein creation of surface roughness is added at the granulation stage and/or the firing stage. 
     
     
         17 . The method of  claim 16  wherein ceramic, polymer, metallic, glass, cement materials or mixtures thereof are added to a pelletizer before the granulation stage. 
     
     
         18 . The method of  claim 17  wherein powder, granules or fibers and their combinations, or various agglomerates of ceramic, polymer, metallic, glass, and cement powders and/or fibers and mixtures thereof are the raw material. 
     
     
         19 . The method of  claim 16  wherein the roughness-producing treatment is carried out in several stages, thereby these stages are intermitted by a powdering stage. 
     
     
         20 . The method of  claim 17  wherein various forms of roughness and irregularities are created at different stages after the granulation stage. 
     
     
         21 . The method of  claim 16  wherein a tackifying agent is additionally used for higher adhesion between a roughness particulate and a granule surface. 
     
     
         22 . The method of  claim 21  wherein the tackifying agent is deposited as a thin layer on the granules before the roughness stage and/or it is mixed with particulate for making roughness. 
     
     
         23 . The method of  claim 14  wherein the proppant comprises a strengthening ceramic, glass, polymer, metallic, cement coating or mixture thereof deposited on proppant particles before a firing stage. 
     
     
         24 . The method of  claim 23  wherein the firing stage has the temperature high enough for partial flashing of ceramic surface and buckling of surface during the firing stage. 
     
     
         25 . The method of  claim 16  wherein an additional layer is deposited on the granule with the melting temperature below the melting temperature of basic material of granule. 
     
     
         26 . The method of  claim 16  wherein the powdering of the semi-finished granule during the granulation stage is carried out with a powder with the melting temperature below the melting temperature of basic material of granule. 
     
     
         27 . The method of  claim 16  wherein the firing stage is followed by adding of ceramic, polymeric, metallic, glass, cement powders and/or fibers or mixtures thereof; the said materials stick to proppant and create at least one form of roughness and irregularities. 
     
     
         28 . The method of  claim 14  provided the rough surface of the proppant is not a polymer coating. 
     
     
         29 . The method of  claim 14  wherein the rough surface of the proppant has same or higher hardness than the particle used to form the rough surfaced proppant. 
     
     
         30 . A method comprising:
 (a) providing a proppant with a rough surface, the proppant comprising a particle coated with a tackifying substance and a roughness element, provided the roughness element does not comprises a polymer; and,   (b) delivering the proppant to a fracture created in a subterranean formation by hydrofracturing operation.   
     
     
         31 . The method of  claim 30  whereby at least a significant prevention of flowback of the proppant is realized while maintaining high proppant pack permeability. 
     
     
         32 . The method of  claim 30  wherein the roughness element has same or higher hardness than the particle. 
     
     
         33 . A method of proppant flowback prevention comprising:
 (a) providing a proppant with a rough surface, the proppant comprising a particle and a roughness element disposed thereupon, provided the roughness element has same or higher hardness than the particle;   (b) delivering the proppant to a fracture created in a subterranean formation by hydrofracturing operation; and   (c) forming a high permeability proppant pack in the fracture.