Method and apparatus for downhole installation of coiled tubing strings

Abstract

A tool for releasably coupling a coiled tubing string to a primary tubing string includes: a tool body for coupling to a downstream end of the primary tubing string, the tool body comprising a locking mechanism for selectively coupling a coiled tubing end joint to the tool body, the locking mechanism being unlockable in response to fluid pressure inside the tool body exceeding a first threshold; a wellbore access mechanism openable in response to fluid pressure inside the tool exceeding a second threshold.

1 . A tool for releasably coupling a coiled tubing string to a primary tubing string, the tool comprising:
 a tool body for coupling to a downstream end of the primary tubing string, the tool body comprising a locking mechanism for selectively coupling a coiled tubing end joint to the tool body, the locking mechanism being unlockable in response to fluid pressure inside the tool body exceeding a first threshold;   a wellbore access mechanism openable in response to fluid pressure inside the tool exceeding a second threshold.   
     
     
         2 . The tool of  claim 1 , wherein the wellbore access mechanism is located upstream of the tool body. 
     
     
         3 . The tool of  claim 1 , comprising a rotating shear joint coupled to the coiled tubing end joint for receiving an end of the coiled tubing string. 
     
     
         4 . The tool of  claim 1 , comprising a clamp coupled to a coupler of the primary tubing string, the clamp for receiving the coiled tubing string at a location along a length of the primary tubing string. 
     
     
         5 . The tool of  claim 1 , wherein the tool body comprises:
 a first end for coupling to a primary tubing string;   a second end for coupling to a primary tubing end joint;   an inner surface defining a channel and first and second bores, the channel for receiving fluid from an outlet of the primary tubing string, the first and second bores being in fluid communication with the channel through openings located adjacent an upstream end of the first and second bores; and   a coiled tubing string support for receiving an end joint of the coiled tubing string;   first and second pistons slidably received in the first and second bores;   first and second cams coupled to the outer surface of a tool body housing at locations circumferentially spaced on either side of the coiled tubing string support, the first and second cams being movable between a locked position in which the cams abut an upstream side of a radially extending structure of the coiled tubing string end joint and an unlocked position in which the first and second cams are radially spaced from the radially extending structure, the first and second cams being biased toward the locked position and being movable in response to movement of the first and second pistons;   wherein when fluid pressure within the tool body exceeds the first threshold, the first piston and the second piston are actuated to move the first cam and the second cams to the unlocked position for releasing the coiled tubing string and when the fluid pressure within the tool body exceeds the second threshold, the channel of the tool body being opened.   
     
     
         6 . The tool of  claim 1 , wherein the tool body comprises:
 a coiled tubing receiving channel for receiving a downstream portion of the coiled tubing end joint;   a first end for coupling to a transition member, the transition member for receiving an upstream portion of the coiled tubing end joint to direct the coiled tubing end joint into the coiled tubing receiving channel;   first and second bores for receiving fluid from an outlet of the primary tubing string,   first and second pistons slidably received in the first and second bores;   first and second cams coupled to the outer surface of the housing at locations circumferentially spaced on either side of the coiled tubing string support, the first and second cams being movable between a locked position in which the cams abut an upstream side of a radially extending structure of the coiled tubing string end joint and an unlocked position in which the first and second cams are radially spaced from the radially extending structure, the first and second cams being biased toward the locked position and being movable in response to movement of the first and second pistons;   wherein when fluid pressure within the tool body exceeds the first threshold, the first piston and the second piston are actuated to move the first cam and the second cams to the unlocked position for releasing the coiled tubing string.   
     
     
         7 . The tool of  claim 6 , wherein the first and second bores receive fluid through a pressure line for communicating with the outlet, the pressure line extending through the transition member. 
     
     
         8 . The tool of  claim 1 , wherein the wellbore access mechanism comprises:
 a fitting for coupling to a downstream end of the primary tubing string, the fitting comprising slots extending through a wall of the fitting;   a piston slidable though a channel of the fitting between a first position in which communication between the channel and the wellbore is blocked and a second position in which communication between the channel and the wellbore is open; and   shear pins coupling the piston to the fitting;   wherein the shear pins fail in response to the fluid pressure exceeding the second threshold to release the piston to the second position.   
     
     
         9 . The tool of  claim 1 , comprising a transition member between the tool body and the wellbore access mechanism, the transition member for transitioning the coiled tubing end joint into a position within the tool body. 
     
     
         10 . The tool of  claim 1 , wherein the tool body is bullnose-shaped. 
     
     
         11 . The tool of  claim 5 , wherein the first and second pistons are fitted with snap rings. 
     
     
         12 . The tool of  claim 6 , wherein the first and second pistons are fitted with snap rings. 
     
     
         13 . A clamp assembly for coupling a coiled tubing string to a primary tubing string, the clamp assembly comprising;
 a coupler for coupling adjacent primary tubing members of the primary tubing string to one another;   a clamp coupled to the coupler, the clamp comprising a hinge and a bracket located opposite the hinge, the bracket for receiving the coiled tubing string;   wherein the bracket is sized for limiting non-axial movement of the coiled tubing string relative to the primary tubing string.   
     
     
         14 . The clamp assembly of  claim 13 , wherein the clamp comprises cutouts for receiving axially extending projections of the coupler to couple the clamp to the primary tubing string. 
     
     
         15 . The clamp assembly of  claim 13 , wherein the clamp assembly is openable for receiving the primary tubing string by pivoting first and second clamp members about a hinge pin of the hinge. 
     
     
         16 . The clamp assembly of  claim 14 , comprising a second clamp coupled to axially extending projections extending from an opposite end of the coupler. 
     
     
         17 . The clamp assembly of  claim 14 , wherein the axially extending projections comprise circumferentially extending openings for receiving fasteners to couple the clamp to the coupler.