Multizone and zone-by-zone abrasive jetting tools and methods for fracturing subterranean formations

Abstract

One or more fluid-jetting subs having jet ports and a packer element are incorporated into a completion string for deployment into a wellbore for perforation and treatment operations. The packer element, being either an inflatable packer element or a compressible packer element, is downhole of the jet ports and is fluid pressure actuated. Pressure in the completion string is maintained at a pressure higher than in the annulus thereabout to keep the packer set for sealing the annulus therebelow while fluid is delivered through the jet ports for perforating or treatment such as fracturing.

1 . A fluid-jetting sub, deployable into a wellbore on a completion string and forming an annulus therebetween, for use in perforating and fracturing a subterranean formation comprising:
 a tubular housing adapted for connection to the completion string and having a tool bore formed therethrough being contiguous with a bore of the completion string;   a plurality of jet ports extending substantially radially through the tubular housing;   a packer element formed circumferentially about the housing downhole of the plurality of jet ports and adapted to seal the annulus when actuated to a set position; and   a fluid block formed in the bore of the housing downhole of at least the plurality of jet ports for at least temporarily blocking a flow of fluid through the tool bore therebelow,   wherein when the fluid is at least temporarily blocked, the fluid in the tool bore   is caused to exit the plurality of jet ports for delivering fluid therethrough for perforating and fracturing the formation; and   to operatively engage the packer element for actuating the packer element to the set position.   
     
     
         2 . The fluid-jetting sub of  claim 1  wherein the packer element is an inflatable element, the sub further comprising:
 one or more packer ports extending radially through the housing for fluidly connecting between the tool bore and the packer element uphole of the fluid block, the fluid entering the one or more packer ports for operatively engaging the packer element for inflating the packer element to the set position. 
 
     
     
         3 . The fluid-jetting sub of  claim 2  further comprising a sliding sleeve positioned within the tool bore and axially moveable therein to cover the plurality of jet ports and the one or more packer ports in a closed position and to open the plurality of jet ports and the one or more packer ports in an open position. 
     
     
         4 . The fluid-jetting sub of  claim 3  further comprising:
 a ball seat operatively connected to the sleeve and adapted to receive a ball dropped into the bore of the housing for forming the fluid block, fluid pressure acting at the fluid block for axially moving the sleeve from the closed position to the open position for delivering fluid through the plurality of jet ports and through the one or more packer ports. 
 
     
     
         5 . The fluid-jetting sub of  claim 1  wherein the packer element is a compressible element, the sub further comprising:
 a ball seat operatively engaging the packer element and adapted to receive a ball dropped into the bore of the housing for forming the fluid block, fluid pressure acting at the ball sealed in the ball seat for compressing the packer element to the set position. 
 
     
     
         6 . The fluid-jetting sub of  claim 5  further comprising:
 a sliding sleeve positioned within the tool bore and axially moveable therein to cover the plurality of jet ports in a closed position, the sliding sleeve being operatively connected to the packer element, the ball seat being formed on the sliding sleeve, wherein 
 fluid pressure acting at the ball sealed in the ball seat moves the sliding sleeve axially from the closed position to an open position for opening the plurality of jet ports and for acting to compress the packer element to the set position. 
 
     
     
         7 . A completion tool deployable into a wellbore on a completion string and forming an annulus therebetween for use in perforating and fracturing a subterranean formation comprising:
 one or more fluid-jet subs incorporated in the completion string, each of the one or more fluid-jet subs having   a tubular housing connectable within the completion string and having a tool bore formed therethrough being contiguous with a bore of the completion string;   a plurality of jet ports extending substantially radially through the tubular housing;   a packer element formed circumferentially about the housing downhole of the plurality of jet ports for sealing the annulus when actuated to a set position; and   a fluid block formed in the bore of the housing downhole of at least the plurality of jet ports for at least temporarily blocking a flow of fluid through the tool bore therebelow,   wherein when the fluid is at least temporarily blocked, the fluid flowing through the bores of the tubing string and the fluid-jet sub
 is caused to exit the plurality of jet ports for delivering fluid therethrough for perforating and fracturing the formation; and 
 to operatively engage the packer element for actuating the packer element to the set position. 
   
     
     
         8 . The completion tool of  claim 7  wherein the completion string is a jointed tubular string and the one or more fluid-jetting subs is two or more fluid-jet subs, the two or more fluid-jet subs are spaced along the jointed tubular string for positioning at zones of interest in the formation. 
     
     
         9 . The completion tool of  claim 7  wherein the completion string as coiled tubing and the one or more fluid-jetting subs is one fluid-jetting sub, the fluid-jetting sub being positioned adjacent a distal end of the coiled tubing for positioning at zones of interest in the formation. 
     
     
         10 . A method for completion of a wellbore comprising:
 incorporating one or more fluid jetting subs into a completion tubing string deployed into a wellbore and forming an annulus therebetween, each of the one or more fluid jetting subs having
 a housing having a bore formed therethrough contiguous with a bore of the completion string; 
 one or more jet ports extending radially through the housing and; 
 a packer element formed about the housing therebelow; 
   at least temporarily blocking the flow of fluid through the tool bore below at least the jet ports;   flowing fluid through the contiguous bore for increasing pressure within the tool bore to greater than outside the housing, the pressure acting to actuate the packer element to a set position and to jet fluid through the one or more jet ports for jetting perforations in at least the wellbore; and   maintaining the pressure in the tool bore greater than outside the housing to maintain the packer element in the set position while providing treatment fluid through the completion string or through the annulus for treating the formation through the perforations.