Proppant for use in hydraulic fracturing to stimulate a well

Abstract

A proppant for use in hydraulic fracturing to stimulate a well is provided. The proppant is fly ash particles having a mean particle size (d50) of between 45 μm and 150 μm and a size distribution defined by (d10)≦5 μm and (d98)≦250 μm.

1 . A proppant for use in hydraulic fracturing to stimulate a well, comprising:
 fly ash particles having a mean particle size (d50) of between 45 μm and 150 μm and a size distribution defined by (d10)≦5 μm and a (d98)≦250 μm.   
     
     
         2 . The proppant of  claim 1 , wherein said fly ash particles have a particle roundness and sphericity of great than 0.8 as determined by ISO 13503-2006 (E), part 7. 
     
     
         3 . The proppant of  claim 2 , wherein said fly ash particles have a hydraulic conductivity of 1×10 −3  cm/sec or less as determined by falling head method. 
     
     
         4 . The proppant of  claim 3 , wherein said fly ash particles have an absolute density of less than 2.4 g/cm 3  as determined by part 10.5 of ISO 13503-2006 (E). 
     
     
         5 . The proppant of  claim 4 , wherein said fly ash particles have a bulk density of less than 1.1 g/cm 3  as determined by part 10.3 of ISO 13503-2006 (E). 
     
     
         6 . The proppant of  claim 5 , wherein said fly ash particles have a void volume of greater than 45% as calculated from absolute volume (AV) and bulk specific volume (BV) as derived from the inverse of bulk density and absolute density. 
     
     
         7 . The proppant of  claim 6 , wherein said fly ash particles have a loss on ignition of less than 6% as determined by part 12 of ISO 13503-2006 (E). 
     
     
         8 . A proppant for use in hydraulic fracturing to stimulate a well, comprising:
 fly ash particles having a mean particle size (d50) of between 80 μm and 100 μm and a size distribution defined by (d5)≦5 μm and a (d99.5)≦250 μm.   
     
     
         9 . The proppant of  claim 8 , wherein said fly ash particles have a particle roundness and sphericity of great than 0.9 as determined by ISO 13503-2006 (E), part 7. 
     
     
         10 . The proppant of  claim 9 , wherein said fly ash particles have a hydraulic conductivity of 1.5×10 −2  cm/sec or less as determined by falling head method. 
     
     
         11 . The proppant of  claim 10 , wherein said fly ash particles have an absolute density of less than 2.3 g/cm 3  as determined by part 10.5 of ISO 13503-2006 (E). 
     
     
         12 . The proppant of  claim 11 , wherein said fly ash particles have a bulk density of less than 1.0 g/cm 3  as determined by part 10.3 of ISO 13503-2006 (E). 
     
     
         13 . The proppant of  claim 12 , wherein said fly ash particles have a void volume of greater than 50% as calculated from absolute volume (AV) and bulk specific volume (BV) as derived from the inverse of bulk density and absolute density. 
     
     
         14 . The proppant of  claim 13 , wherein said fly ash particles have a loss on ignition of less than 2% as determined by part 12 of ISO 13503-2006 (E). 
     
     
         15 . A method of hydraulic fracturing of a subterranean formation having a well bore, comprising:
 injecting into said well bore a slurry containing a first proppant at sufficiently high rates and pressures to fracture said subterranean formation to accept said slurry, said first proppant comprising fly ash particles as set forth in  claim 1 .   
     
     
         16 . The method of  claim 15 , including injecting a second proppant into said well bore with said first proppant, said second proppant having a larger mean particle size than said first proppant. 
     
     
         17 . The method of  claim 15 , including injecting a second proppant into said well bore after said first proppant, said second proppant having a larger mean particle size than said first proppant. 
     
     
         18 . A method of hydraulic fracturing of a subterranean formation having a well bore, comprising:
 injecting into said well bore a slurry containing a first proppant at sufficiently high rates and pressures to fracture said subterranean formation to accept said slurry, said first proppant comprising fly ash particles as set forth in  claim 8 .   
     
     
         19 . The method of  claim 18 , including injecting a second proppant into said well bore with said first proppant, said second proppant having a larger mean particle size than said first proppant. 
     
     
         20 . The method of  claim 18 , including injecting a second proppant into said well bore after said first proppant, said second proppant having a larger mean particle size than said first proppant.