System and method of injecting a proppant mixture during fracturing

Abstract

A method of forming an elevated pressure proppant-containing fracturing fluid for direct injection into a wellbore that reduces exposure of a substantial amount of the pumping equipment to the abrasive effects of proppant, as compared to conventional pumping equipment. The method includes providing a high pressure fluid stream to a nozzle having an inlet and an exit; accelerating the high pressure fluid stream through the nozzle from the inlet to the exit to increase the velocity thereof; providing a low pressure stream comprising a proppant to a suction chamber, the suction chamber positioned adjacent the nozzle exit; and mixing the low pressure fluid stream comprising a proppant with the high pressure fluid stream to form an elevated pressure proppant-containing fracturing fluid. A method for fracturing and a system for forming an elevated pressure proppant-containing fracturing fluid for injection into a wellbore are also provided.

1 . A method of forming an elevated pressure proppant-containing fracturing fluid for direct injection into a wellbore that reduces exposure of a substantial amount of the pumping equipment to the abrasive effects of proppant, as compared to conventional pumping equipment; the method comprising the steps of:
 a) providing a high pressure fluid stream to a nozzle having an inlet and an exit;   b) accelerating the high pressure fluid stream through the nozzle from the inlet to the exit to increase the velocity thereof;   c) providing a low pressure stream comprising a proppant to a suction chamber, the suction chamber positioned adjacent the nozzle exit; and   d) mixing the low pressure fluid stream comprising a proppant with the high pressure fluid stream to form an elevated pressure proppant-containing fracturing fluid.   
     
     
         2 . The method of  claim 1 , wherein the high pressure fluid stream is provided from a source of substantially proppant-free fluid. 
     
     
         3 . The method of  claim 2 , wherein the substantially proppant-free high pressure fluid stream is provided by a high pressure pump. 
     
     
         4 . The method of  claim 3 , wherein the high pressure pump is a centrifugal pump. 
     
     
         5 . The method of  claim 4 , wherein the centrifugal pump is a multi-stage centrifugal pump. 
     
     
         6 . The method of  claim 5 , wherein the multi-stage centrifugal pump is powered by a turbine. 
     
     
         7 . The method of  claim 3 , wherein the high pressure pump is a positive displacement pump. 
     
     
         8 . The method of  claim 1 , wherein the nozzle and suction chamber form an eductor. 
     
     
         9 . The method of  claim 8 , wherein the eductor further comprises an outlet end in fluid communication with a well. 
     
     
         10 . The method of  claim 1 , further comprising the step of passing elevated pressure proppant-containing fracturing fluid through one or more mixing baffles. 
     
     
         11 . The method of  claim 1 , further comprising the step of adding a viscosity modifying additive to the low pressure stream comprising a proppant. 
     
     
         12 . A method of fracturing a formation penetrated by a well, the method comprising the steps of:
 a) providing a substantially proppant-free fluid stream to an inlet of a high pressure pump;   b) pressurizing the substantially proppant-free fluid stream to form a high pressure substantially proppant-free fluid stream;   c) feeding the substantially proppant-free high pressure fluid stream to a nozzle having an inlet and an exit;   d) accelerating the high pressure substantially proppant-free fluid stream through the nozzle from the inlet to the exit to increase the velocity thereof;   e) providing a low pressure stream comprising a proppant to a suction chamber, the suction chamber positioned adjacent the nozzle exit;   f) mixing the low pressure fluid stream comprising a proppant with the high pressure fluid stream to form an elevated pressure proppant-containing fracturing fluid; and   g) injecting the elevated pressure proppant-containing fracturing fluid into the well.   
     
     
         13 . The method of  claim 12 , wherein the substantially proppant-free high pressure fluid stream is provided by a high pressure pump. 
     
     
         14 . The method of  claim 13 , wherein the high pressure pump is a centrifugal pump. 
     
     
         15 . The method of  claim 14 , wherein the centrifugal pump is a multi-stage centrifugal pump. 
     
     
         16 . The method of  claim 15 , wherein the multi-stage centrifugal pump is powered by a turbine. 
     
     
         17 . The method of  claim 12 , wherein the nozzle and suction chamber form an eductor. 
     
     
         18 . The method of  claim 17 , wherein the eductor further comprises an outlet end in fluid communication with a well. 
     
     
         19 . The method of  claim 12 , further comprising the step of passing elevated pressure proppant-containing fracturing fluid through one or more mixing baffles. 
     
     
         20 . The method of  claim 12 , further comprising the step of adding a viscosity modifying additive to the low pressure stream comprising a proppant. 
     
     
         21 . A system for forming an elevated pressure proppant-containing fracturing fluid for injection into a wellbore that reduces exposure of a substantial amount of the pumping equipment to the abrasive effects of proppant, as compared to conventional pumping equipment, comprising
 a) at least one high pressure pump having an inlet and an outlet, for pressurizing a substantially proppant-free fluid;   b) at least one low pressure pump having an inlet and an outlet, for pressurizing a proppant-containing fluid; and   c) at least one eductor, the at least one eductor comprising a nozzle having an inlet and an outlet, a suction chamber and an eductor outlet, the nozzle inlet in fluid communication with the outlet of the at least one high pressure pump, the suction chamber in fluid communication with the outlet of the at least one low pressure pump and the eductor outlet in fluid communication with the well.   
     
     
         22 . The system of  claim 21 , wherein the high pressure pump is a centrifugal pump. 
     
     
         23 . The system of  claim 22 , wherein the centrifugal pump is a multi-stage centrifugal pump. 
     
     
         24 . The system of  claim 23 , wherein the multi-stage centrifugal pump is powered by a turbine. 
     
     
         25 . The system of  claim 21 , further comprising one or more mixing baffles positioned downstream of the eductor outlet. 
     
     
         26 . The system of  claim 21 , further comprising blast joints positioned upstream and/or downstream of the eductor nozzle inlet. 
     
     
         27 . The system of  claim 21 , wherein a plurality of high pressure pumps for pressurizing a substantially proppant-free fluid, a low pressure pump for pressurizing a proppant-containing fluid, and an eductor are structured and arranged to provide elevated pressure proppant-containing fracturing fluid for injection into a well. 
     
     
         28 . A method of increasing the service life of a high pressure pump used in a system for forming an elevated pressure proppant-containing fracturing fluid for direct injection into a wellbore that reduces exposure of a substantial amount of the pumping equipment to the abrasive effects of proppant, as compared to conventional pumping equipment; the method comprising the steps of:
 a) providing a substantially proppant-free fluid stream to an inlet of a high pressure pump;   b) pressurizing the substantially proppant-free fluid stream to form a high pressure substantially proppant-free fluid stream;   c) feeding the substantially proppant-free high pressure fluid stream to a nozzle having an inlet and an exit;   d) accelerating the high pressure fluid stream through the nozzle from the inlet to the exit to increase the velocity thereof;   e) providing a low pressure stream comprising a proppant to a suction chamber, the suction chamber positioned adjacent the nozzle exit; and   f) mixing the low pressure fluid stream comprising a proppant with the high pressure fluid stream to form an elevated pressure proppant-containing fracturing fluid.   
     
     
         29 . The method of  claim 28 , wherein the high pressure fluid stream is provided from a source of substantially proppant-free fluid. 
     
     
         30 . The method of  claim 29 , wherein the substantially proppant-free high pressure fluid stream is provided by a high pressure pump. 
     
     
         31 . The method of  claim 30 , wherein the high pressure pump is a centrifugal pump. 
     
     
         32 . The method of  claim 31 , wherein the centrifugal pump is a multi-stage centrifugal pump. 
     
     
         33 . The method of  claim 32 , wherein the high pressure pump is a positive displacement pump. 
     
     
         34 . The method of  claim 28 , wherein the nozzle and suction chamber form an eductor. 
     
     
         35 . The method of  claim 34 , wherein the eductor further comprises an outlet end in fluid communication with a well. 
     
     
         36 . The method of  claim 28 , further comprising the step of passing elevated pressure proppant-containing fracturing fluid through one or more mixing baffles.