System and process for extracting oil and gas by hydraulic fracturing

Abstract

A fracturing system is described. The system includes an electric motor-driven pumping sub-system, configured to pump a pressurized fracturing fluid into at least one wellbore, under high pressure conditions sufficient to increase the downhole pressure of the wellbore, to exceed that of the fracture gradient of the solid matter surrounding the wellbore. The system also includes an electric power generation sub-system that provides energy to the pumping sub-system. The electric power generation sub-system includes a multitude of electric motors that are powered by a single electrical feed source. A related process for extracting hydrocarbons from a reservoir rock formation by the fracturing operation is also described.

What is claimed: 
     
         1 . A hydraulic fracturing system, comprising
 a) an electric motor-driven pumping sub-system, configured to pump a pressurized fracturing fluid into at least one wellbore, under high pressure conditions sufficient to increase the downhole pressure of the wellbore, to exceed that of the fracture gradient of the solid matter surrounding the wellbore; and   b) an electric power generation sub-system that provides energy to the pumping sub-system, comprising a multitude of electric motors that are powered by a single electrical feed source.   
     
     
         2 . The fracturing system of  claim 1 , wherein the pumping sub-system comprises one or more platforms, and each platform supports one or more pumping units that each comprise at least one pump and at least one electric motor. 
     
     
         3 . The fracturing system of  claim 2 , wherein each electric motor is configured to provide power for one pump. 
     
     
         4 . The fracturing system of  claim 2 , wherein each pumping unit comprises two pump-motor sets. 
     
     
         5 . The fracturing system of  claim 1 , wherein the electrical feed source comprises an electrical feeder that is connected, directly or indirectly, to an electrical transmission line, a power sub-station, a power generation facility, or a dedicated power generation sub-system. 
     
     
         6 . The fracturing system of  claim 1 , wherein the electrical feed source comprises at least one gas turbine engine. 
     
     
         7 . The fracturing system of  claim 1 , wherein the electric power generation sub-system is powered by a large generator capable of supplying greater than about 15 MW of power. 
     
     
         8 . The fracturing system of  claim 7 , where the electric power generation sub-system is further powered by at least one gas engine capable of supplying about 1 MW to about 10 MW of power. 
     
     
         9 . The fracturing system of  claim 1 , wherein the pumping sub-system comprises at least one variable-frequency drive (VFD). 
     
     
         10 . The fracturing system of  claim 9 , wherein the variable-frequency drive is configured to control electrical current from the electrical feed source, according to desired parameters. 
     
     
         11 . The fracturing system of  claim 10 , wherein the variable-frequency drive is configured to direct the electrical current to at least one designated pumping unit. 
     
     
         12 . A process for extracting hydrocarbons from a reservoir rock formation by a hydraulic fracturing operation, comprising the step of introducing a hydraulic fracturing treatment fluid into a subterranean formation at a pressure sufficient to form or to enhance at least one fracture within the subterranean formation,
 wherein the fracturing treatment fluid is pumped into at least one wellbore in the subterranean formation by an electric motor-driven pumping sub-system, configured to pump the fluid into the wellbore under high pressure conditions sufficient to increase the downhole pressure of the wellbore, to exceed that of the fracture gradient of the solid matter surrounding the wellbore; and   wherein the pumping sub-system is energized by an electric power generation sub-system that provides energy to the pumping sub-system, and the power generation sub-system comprises a multitude of electric motors that are powered by a single electrical feed source.   
     
     
         13 . The process of  claim 12 , wherein the pumping sub-system comprises one or more platforms, and each platform supports one or more pumping units that each comprise at least one pump and at least one electric motor. 
     
     
         14 . The process of  claim 13 , wherein each electric motor is configured to provide power for one pump. 
     
     
         15 . The process of  claim 13 , wherein each pumping unit comprises two pump-motor sets. 
     
     
         16 . The process of  claim 12 , wherein the electrical feed source comprises an electrical feeder that is connected, directly or indirectly, to an electrical transmission line, a power sub-station, a power generation facility, or a dedicated power generation sub-system.