System and method for fracturing a hydrocarbon producing formation

Abstract

A system and method for fracturing a hydrocarbon producing formation in which a fracturing tool is inserted in a wellbore adjacent the formation, and fracturing fluid is introduced into the annulus between the fracturing tool and the wellbore and flows to the formation.

1 . A method of fracturing a subterranean formation penetrated by a wellbore, comprising the steps of: 
 (a) positioning a fracturing tool within the wellbore, wherein the fracturing tool has a fracturing tool outer wall;    (b) initiating a fracture having a center of fracture point, wherein the center of fracture point is located within the subterranean formation but not within the wellbore; and    (c) creating the fracture.    
   
   
       2 . The method of  claim 1  wherein the wellbore comprises a substantially vertical section, and step (a) further comprises the step of positioning the fracturing tool within the substantially vertical portion of the wellbore.  
   
   
       3 . The method of  claim 1  wherein the wellbore comprises a substantially horizontal section, and step (a) further comprises the step of positioning the fracturing tool within the substantially horizontal portion of the wellbore.  
   
   
       4 . The method of  claim 1  wherein the fracturing tool comprises nozzles.  
   
   
       5 . The method of  claim 4  wherein the nozzles are angled at an acute angle to the fracturing tool outer wall.  
   
   
       6 . The method of  claim 5  wherein the center of fracture point is at an acute angle to the fracturing tool outer wall.  
   
   
       7 . The method of  claim 1  wherein: 
 the fracturing tool comprises a hydrajetting tool assembly mechanically connected to a work string;    the work string comprises an outer wall and an inner wall; and    the hydrajetting tool assembly comprises: 
 a hydrajetting sub defined by an outer wall and an inner fluid flow passageway;  
 a port formed through the outer wall of the hydrajetting sub and adapted to communicate with the inner fluid flow passageway;  
 a nozzle mounted within the port; and  
 a directional sub, wherein the directional sub is mechanically connected to the hydrajetting sub.  
   
   
   
       8 . A method of fracturing a subterranean formation penetrated by a wellbore, comprising the steps of: 
 (a) positioning a hydrajetting tool assembly within the wellbore, wherein the hydrajetting tool assembly comprises: 
 a hydrajetting sub defined by an outer wall and an inner fluid flow passageway;  
 a port formed through the outer wall and adapted to communicate with the inner fluid flow passageway;  
 a nozzle mounted within the port; and  
 a directional sub, wherein the directional sub is mechanically connected to the hydrajetting sub;  
   (b) initiating a fracture having a center of fracture point by introducing a fracturing fluid into the inner fluid flow passageway of the hydrajetting sub and jetting the fracturing fluid through the nozzle against the subterranean formation at a pressure sufficient to form cavities in the formation, wherein the center of fracture point is located within the subterranean formation but not within the wellbore, and the cavities in the subterranean formation are in fluid communication with the wellbore; and    (c) creating the facture by maintaining the fracturing fluid in the cavities while jetting at a sufficient static pressure to fracture the subterranean formation.    
   
   
       9 . The method of  claim 8  further comprising prior to step (b) the steps of: 
 establishing a desired orientation of the hydrajetting tool assembly;    determining the orientation of the hydrajetting tool assembly with the directional sub; and    rotating the hydrajetting tool so that the orientation of hydrajetting tool assembly equals the desired orientation of the hydrajetting tool assembly.    
   
   
       10 . The method of  claim 8  wherein the hydrajetting tool assembly further comprises a packer, and the method further comprises the step of forming a seal to prevent fluid flow downstream of the seal and to permit the flow of the fracturing fluid into the subterranean formation.  
   
   
       11 . The method of  claim 10  wherein the step of forming the seal comprises the steps of: 
 connecting the packer to the hydrajetting tool assembly; and    setting the packer.    
   
   
       12 . The method of  claim 8  further comprising the steps of: 
 adding a propping agent to the fracturing fluid; and    propelling the propping agent into the cavities.    
   
   
       13 . The method of  claim 8  further comprising the step of adding a consolidation agent to the fracturing fluid.  
   
   
       14 . The method of  claim 8  wherein the consolidation agent is a resin coated proppant.  
   
   
       15 . The method of  claim 8  further comprising following step (c) the step of packing the wellbore by introducing a fluid slurry into wellbore.  
   
   
       16 . The method of  claim 15  wherein the fluid slurry comprises gravel.  
   
   
       17 . A hydrajetting tool assembly comprising: 
 a hydrajetting sub defined by an outer wall and an inner fluid flow passageway;    a port formed through the outer wall and adapted to communicate with the inner fluid flow passageway;    a nozzle mounted within the port; and    a directional tool, wherein the directional tool is mechanically connected to the hydrajetting sub.    
   
   
       18 . The hydrajetting tool assembly of  claim 17  wherein the nozzle is comprised of tungsten carbide or ceramic.  
   
   
       19 . The hydrajetting tool assembly of  claim 17  wherein the nozzle extends beyond the outer wall and is oriented at an angle between about 30 degrees and about 90 degrees relative to the outer wall.  
   
   
       20 . The hydrajetting tool assembly of  claim 19  wherein the nozzle is oriented at an angle between about 45 degrees and about 90 degrees relative to the outer wall.  
   
   
       21 . The hydrajetting tool assembly of  claim 17  wherein the port is approximately circular.  
   
   
       22 . The hydrajetting tool assembly of  claim 17  wherein: 
 the hydrajetting tool assembly is mechanically connected to a work string;    the work string comprises: 
 an outer wall;  
 an inner wall;  
 a non-conducting material; and  
 a conducting material between the work string outer wall and the work string inner wall; and  
   the hydrajetting tool assembly is capable of communicating with surface equipment through the conducting material    
   
   
       23 . The hydrajetting tool assembly of  claim 17  further comprising a mud pulse or sonic generator connected to the hydrajetting sub.  
   
   
       24 . The hydrajetting tool assembly of  claim 17  further comprising a plurality of ports and a plurality of nozzles, wherein the nozzles are mounted within the ports.  
   
   
       25 . The hydrajetting tool assembly of  claim 24  wherein the nozzles are oriented in an approximately unitary direction.  
   
   
       26 . The hydrajetting tool assembly of  claim 24  wherein the nozzles are located in two rows arranged longitudinally along the hydrajetting sub, and the rows are located 180° apart.  
   
   
       27 . The hydrajetting tool assembly of  claim 17  further comprising a downhole power unit mechanically connected to the hydrajetting sub.  
   
   
       28 . The hydrajetting tool assembly of  claim 27  wherein the downhole power unit comprises a battery, fuel cell, or fluid motor and generator.  
   
   
       29 . The hydrajetting tool assembly of  claim 17  further comprising a rotating sleeve mechanically connected to the hydrajetting sub.  
   
   
       30 . The hydrajetting tool assembly of  claim 29  further comprising a downhole power unit mechanically connected to the rotating sleeve.  
   
   
       31 . The hydrajetting tool assembly of  claim 30  wherein the hydrajetting sub is directly connected to rotating sleeve, and the rotating sleeve is directly connected to the downhole power unit.  
   
   
       32 . The hydrajetting tool assembly of  claim 17  further comprising a check valve mechanically connected to the hydrajetting sub.  
   
   
       33 . The hydrajetting tool assembly of  claim 32  further comprising a temperature sensor.  
   
   
       34 . The hydrajetting tool assembly of  claim 32  further comprising a pressure sensor.  
   
   
       35 . The hydrajetting tool assembly of  claim 17  further comprising a packing device mechanically connected to the hydrajetting sub, wherein the packing device is capable of seating against the wellbore to form a seal.  
   
   
       36 . The hydrajetting tool assembly of  claim 17  wherein the directional tool comprises a gyroscopic surveyor, a wireline steerer, a memory pulsed neutron logging device, or an electromagnetic logging device.  
   
   
       37 . The hydrajetting tool assembly of  claim 36  wherein the directional tool is capable of communicating with surface equipment.  
   
   
       38 . The hydrajetting tool assembly of  claim 36  wherein the directional tool further comprises an integrated power system.  
   
   
       39 . The hydrajetting tool assembly of  claim 17  further comprising a hole finder mechanically connected to the hydrajetting tool.  
   
   
       40 . The hydrajetting tool assembly of  claim 17  further comprising a gamma radiation source mechanically connected to the hydrajetting sub.  
   
   
       41 . The hydrajetting tool assembly of  claim 17  further comprising a collar locator mechanically connected to the hydrajetting sub.