Apparatus To Move An Object In An Open Hole Section of A Wellbore

Abstract

An apparatus to move an object in an open hole section of a wellbore is described. A bottom hole assembly of the apparatus includes a downhole pulling tool and fishing device. The downhole pulling tool includes an open hole anchor to allow location of the downhole pulling tool in the open hole section of the wellbore so as to reduce the operating distance between the downhole pulling tool and the fishing device. An embodiment in which a cut section of tubular is removed from the open hole section is described. A casing cutter may also be located in the bottom hole assembly to cut the tubular on the same trip in the well as removing the cut section of tubular.

1 . An apparatus to move an object in an open hole section of a wellbore, comprising a string for running into the well, the string being arranged to carry a fluid in a throughbore thereof and including a downhole assembly, the downhole assembly comprising:
 a downhole pulling tool, the downhole pulling tool comprising an open hole anchor including an elastomeric anchor element for axially fixing the downhole assembly to a borehole wall of an open section of the wellbore and an inner mandrel axially moveable relative to the anchor in response to the fluid in the throughbore;   a fishing device connected to the inner mandrel for engaging the object;   wherein an increase in fluid pressure in the throughbore operates the downhole pulling tool to anchor the downhole assembly to the borehole wall, raise the inner mandrel relative to the open hole anchor and pull the object.   
     
     
         2 . The apparatus according to  claim 1 , wherein the open hole anchor is re-settable. 
     
     
         3 . The apparatus according to  claim 2 , wherein the elastomeric anchor element comprises an inflatable packer element. 
     
     
         4 . The apparatus according to  claim 2 , wherein the anchor further comprises at least one gripping element to engage the borehole wall in the open hole section. 
     
     
         5 . The apparatus according to  claim 1 , wherein the downhole pulling tool includes a housing supported in the well by the string and enclosing a plurality of axially stacked pistons generating a cumulative axial force, each of the plurality of pistons axially movable in response to the fluid increase in the throughbore; and wherein movement of the pistons also moves the inner mandrel. 
     
     
         6 . The apparatus according to  claim 1 , wherein the fixing device is selected from a group comprising: a spear, an overshot, a grapple and an anchor. 
     
     
         7 . The apparatus according to  claim 6 , wherein the spear comprises: a sliding assembly mounted on the inner mandrel; at least one gripper for gripping onto an inner wall of the object, the gripper being coupled to the sliding assembly; the sliding assembly being operable for moving the gripper between a first position in which the gripper is arranged to grip onto the inner wall of the object in at least one gripping region of the object and a second position in which the gripper is held away from the inner wall; and a switcher which, when advanced into the object, locks the sliding assembly to the inner mandrel with the gripper in the second position; and, when the casing spear is pulled upward out of the stuck object and the switcher exits the end of the object, automatically allows engagement of the object by the gripper in the first position. 
     
     
         8 . The apparatus according to  claim 1 , wherein the downhole assembly includes a valve for blocking the flow of fluid through the throughbore, the valve being located between the downhole pulling tool and the fishing device, wherein the valve is closed by raising the downhole pulling tool relative to the fishing device when the fishing device engages the object and opened by setting pressure down on the downhole pulling tool. 
     
     
         9 . The apparatus according to  claim 1 , wherein the object is a cut section of tubular and the downhole assembly further comprises a cutting tool to cut the tubular and form the cut section of tubular. 
     
     
         10 . The apparatus according to  claim 1 , wherein the downhole assembly further comprises a jetting tool to wash an inner wall of the open hole section.