Latch-and-perf system and method

Abstract

A latch and perf assembly for completion of a wellbore comprises a setting tool with an explosive charge and a wireline connector, a run-in tool installed on the setting tool, a latch installed on the run-in tool and adapted to assume a retracted state during run-in of the assembly and an expanded state when the latch arrives at a predetermined depth in the wellbore and a seal inside the latch adapted to seal against hydraulic pressure applied from surface. The assembly is adapted to be run into the wellbore attached to a wireline, and at least a predetermined part of the seal is adapted to dissolve after fracking of the wellbore.

1 . A latch and perf assembly for completion of a wellbore having a liner, comprising:
 a setting tool comprising at least one explosive charge and a wireline connector;   a run-in tool installed on the setting tool;   a latch installed on the run-in tool and adapted to assume a retracted state during run-in of the assembly, and to assume an expanded state when the explosive charge is detonated, the latch attached to a seal for creating a fluidic seal against hydraulic pressure applied from surface to enable fracking of the wellbore,   wherein the assembly is adapted to be run into the liner attached to a wireline, and at least a predetermined part of the seal is adapted to dissolve after fracking of the wellbore.   
     
     
         2 . The assembly of  claim 1 , wherein the latch comprises:
 a tubular base having a base inner diameter; and   a plurality of fingers extending from the tubular base, and each having a finger tip, the fingers being adapted to enclose a frustoconical internal space with a diameter smaller than the base inner diameter when in the retracted state, and to enclose a substantially cylindrical internal space with a diameter substantially equivalent to the base inner diameter when in the expanded state.   
     
     
         3 . The assembly of  claim 2 , wherein the fingers are adapted to be forced inwardly when in the retracted state, and to autonomously expand when in the expanded state. 
     
     
         4 . The assembly of  claim 2 , wherein each finger has an outwardly extending protrusion at the tip, for enabling the latch to engage a profile provided in the liner at a predetermined depth. 
     
     
         5 . The assembly of  claim 1 , wherein the latch is enabled to engage a profile provided in the liner at a predetermined depth. 
     
     
         6 . The assembly of  claim 1 , wherein the latch is installed on the run-in tool using a retaining sleeve with an uphole end and a downhole end, the latch is joined to the run-in tool at the uphole end with a shearable pin, and the retaining sleeve is adapted to maintain the latch in the retracted state until the pin shears. 
     
     
         7 . The assembly of  claim 6 , wherein the retaining sleeve releases the latch from engagement with the run-in tool using a controlled explosion of a charge triggered by an electrical detonation signal received over the wireline. 
     
     
         8 . The assembly of  claim 6 , wherein the retaining sleeve releases the latch from engagement with the run-in tool in response to an electrical detonation signal received over the wireline. 
     
     
         9 . The assembly of  claim 1 , wherein the seal comprises a ball and a seat, and the predetermined part of the seal is the seat. 
     
     
         10 . The assembly of  claim 1  wherein the setting tool further comprises a perforating gun, wherein the setting tool gun is adapted to be moved uphole to a location of interest upon detonation of the explosive charge, and wherein the perforating gun is adapted to be fired under control of signals transmitted over the wireline. 
     
     
         11 . The assembly of  claim 1 , wherein the latch further comprises means for engagement with a retracting tool once the predetermined part of the seal has dissolved. 
     
     
         12 . The assembly of  claim 9 , wherein the seat is made from a dissolvable material. 
     
     
         13 . The assembly of  claim 9 , wherein the ball is made from a dissolvable material and confined inside the latch when the latch is in the retracted state. 
     
     
         14 . The assembly of  claim 13 , wherein the ball can be made of various material, both degrading and non-degrading. 
     
     
         15 . The assembly of  claim 1 , wherein the liner has a plurality of profiles on its inner surface, the assembly is adapted to be run-in to a predetermined location inside the liner, the setting tool is adapted to release the latch upon detonation of the explosive charge, and the latch is adapted to be pumped into one of the plurality of profiles upon its release from the setting tool. 
     
     
         16 . A fracturing plug for completion of a wellbore, comprising:
 a latch adapted to assume a retracted state during run-in of the fracturing plug in the wellbore, and an expanded state when the fracturing plug arrives at a predetermined depth in the wellbore;   a seat attached to the latch when the latch is in the retracted state, and adapted to seal the wellbore when engaged with a ball under hydraulic pressure when the latch is in the expanded state,   wherein the latch has an internal profile adapted to keep the seat attached to the latch.   
     
     
         17 . A plug-and-perf method of stimulating production of hydrocarbons from a wellbore having a casing, comprising:
 running in a latch and perf assembly attached to a wireline, the assembly including a setting tool, a run-in tool installed on the setting tool, and a fracturing plug with a dissolvable seat attached to the run-in tool;   at a predetermined depth in the wellbore, disengaging the fracturing plug from the run-in tool and causing the fracturing plug to switch from a retracted state to an expanded state;   displacing the fracturing plug downhole using fluid pumped down the liner;   installing the fracturing plug at a target zone of the wellbore;   pressure isolating the target zone from a zone downhole from the target zone by pumping a seal into engagement with the seat;   running in at the target zone a perforating gun;   using the fracking gun to form a plurality of perforations in the casing along the target zone; and,   fracking the target zone.   
     
     
         18 . The method of  claim 17 , wherein the predetermined depth is about 3 m uphole from the target zone. 
     
     
         19 . The method of  claim 17 , wherein the latch and pea assembly is attached to the wireline using a wireline adapter kit. 
     
     
         20 . The method of  claim 17 , further comprising transmission of an electrical detonating signal to the setting tool over the wireline for triggering a small detonation that disengages the fracturing plug from the run-in tool. 
     
     
         21 . The method of  claim 18 , wherein installing the fracturing plug at the target zone is achieved by fitting the fracking plug against an indentation provided in a locator sub provided at the target zone. 
     
     
         22 . The method of  claim 17 , further comprising retrieving the fracturing plug using a retrieving tool. 
     
     
         23 . The method of  claim 17 , wherein the retrieving tool has spring-loaded keys, extending outwardly from the body of the retrieving tool. 
     
     
         24 . The method of  claim 17 , wherein the seal is a dissolvable ball adapted to seal the target zone from a zone downhole from the target zone until the ball has dissolved. 
     
     
         25 . The assembly of  claim 1  wherein the latch comprises a dissolvable material. 
     
     
         26 . The assembly of  claim 1  wherein the latch is adapted to engage a profile of a plurality of profiles provided in a liner installed in the wellbore. 
     
     
         27 . The assembly of  claim 26  wherein the latch is adapted to open a port in the liner upon creation of a seal at the latch, and upon application of a threshold pressure from surface. 
     
     
         28 . The assembly of  claim 27  wherein the port is adapted to be used for hydraulic fracturing upon being opened.