Deployable casing centraliser with latch for bow springs

Abstract

A centraliser for use in a wellbore includes: first and second collars, at least one resilient device extending between the first and second collars, and a locking ring for receiving a tubular in a position radially inside the resilient device and axially between the first and second collars; the resilient device being resiliently biased in a radial direction away from the locking ring; the locking ring having at least one catch device adapted to engage with the at least one resilient device in a radially restricted configuration and the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; and at least one fixing between the at least one catch device and the locking ring and made from a sacrificial material adapted to degrade in wellbore conditions.

1 . A centraliser assembly for use in an oil, gas or water well, the centraliser assembly comprising:
 a centraliser having a body comprising first and second collars, and having a bore with an axis adapted to receive a tubular to be centralised, and at least one resilient device extending between the first and second collars, and   a locking ring for receiving the tubular in a position radially inside the resilient device and axially between the first and second collars;   the resilient device being resiliently biased in a radial direction away from the locking ring towards a radially extended configuration, and being movable radially relative to the locking ring from the radially extended configuration into a radially restricted configuration in which the resilient device is closer to the locking ring than in the radially extended configuration;   the locking ring having at least one catch device adapted to engage with the at least one resilient device in the radially restricted configuration of the resilient device and   wherein the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; and   at least one fixing between the at least one catch device and the locking ring; the at least one fixing comprising a sacrificial material adapted to degrade in wellbore conditions faster than the material of the locking ring or the at least one catch device.   
     
     
         2  The centraliser assembly as claimed in  claim 1 , wherein the at least one resilient device comprises at least one wing protruding circumferentially from an edge of the resilient device. 
     
     
         3  The centraliser assembly as claimed in  claim 2 , wherein the at least one wing extends radially inward from an outer surface of the at least one resilient device. 
     
     
         4  The centraliser assembly as claimed in  claim 1 , wherein the at least one catch device comprises a plate which defines a recess radially inside the plate. 
     
     
         5  The centraliser assembly as claimed in  claim 4 , wherein the recess is adapted to receive a portion of the resilient device. 
     
     
         6  The centraliser assembly as claimed in  claim 1 , wherein a portion of the catch device is adapted to deform when the sacrificial material degrades in borehole conditions. 
     
     
         7  The centraliser assembly as claimed in  claim 1 , wherein the catch device engages a recessed portion of the at least one resilient device in the radially restricted configuration. 
     
     
         8  The centraliser assembly as claimed in  claim 1 , wherein the at least one fixing comprises a pin with a long axis disposed along a radius of the locking ring, perpendicular to the bore of the centraliser body. 
     
     
         9  The centraliser assembly as claimed in  claim 8 , wherein at least a part of the pin passes through at least one aperture in the locking ring and/or the catch device. 
     
     
         10  The centraliser assembly as claimed in  claim 1 , wherein the at least one fixing connects the resilient device and the locking ring. 
     
     
         11  The centraliser assembly as claimed in  claim 1 , wherein the at least one fixing is held in tension, perpendicular to the axis of the bore of the centraliser body. 
     
     
         12  The centraliser assembly as claimed in  claim 1 , wherein the sacrificial material comprises one or more of magnesium, zinc, aluminium manganese and alloys of these. 
     
     
         13  The centraliser assembly as claimed in  claim 1 , incorporating at least one permanent fixing between the at least one catch device and the locking ring. 
     
     
         14  The centraliser assembly as claimed in  claim 1 , wherein at least a portion of the at least one catch device is adapted to remain attached to the at least one resilient device when the sacrificial material degrades and the resilient device moves to the radially extended configuration. 
     
     
         15  The centraliser assembly as claimed in  claim 1 , wherein at least a portion of the at least one catch device is adapted to remain attached to the locking ring when the sacrificial material degrades and the resilient device moves to the radially extended configuration. 
     
     
         16  The centraliser assembly as claimed in  claim 1 , wherein the at least one fixing further comprises a collet and the sacrificial material is a plug inserted into a bore of the collet. 
     
     
         17  A method of centralising a tubular in an oil, gas or water well, the method comprising:
 passing the tubular into an axial bore of a centraliser comprising first and second collars, the centraliser having at least one resilient device extending between the first and second collars, and 
 passing the tubular through a locking ring in a position radially inside the resilient device and axially between the first and second collars; 
 the resilient device being resiliently biased in a radial direction away from the locking ring towards a radially extended configuration, and being movable radially relative to the locking ring from the radially extended configuration into a radially restricted configuration in which the resilient device is closer to the locking ring than in the radially extended configuration; 
 the locking ring having at least one catch device adapted to engage with the at least one resilient device in the radially restricted configuration of the resilient device and 
 wherein the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; 
 wherein at least one fixing extends between the at least one catch device and the locking ring, 
 the at least one fixing comprising a sacrificial material adapted to lose integrity in wellbore conditions faster than the material of the locking ring or the at least one catch device, 
 wherein the method includes:
 deploying the centraliser into the well with the catch engaged with the resilient device and the resilient device in a radially restricted configuration, 
 running the centraliser into the well in the radially restricted configuration, and 
 releasing the catch by at least partially degrading the fixing through contact with fluids in the well before the degradation of the locking ring and the catch device. 
 
 
     
     
         18  The method as claimed in  claim 17 , including engaging the at least one catch device and the at least one resilient device by sliding one of the at least one catch device and the at least one resilient device relative to the other in an axial direction with respect to the bore of the collars. 
     
     
         19  The method as claimed in  claim 17 , including securing the catch device to the locking ring by the at least one fixing in the radially restricted configuration and releasing at least a portion of the catch device from the locking ring in the radially extended configuration. 
     
     
         20  The method as claimed in  claim 17 , including tensioning the at least one fixing along an axis perpendicular to the axis of the bore of the body. 
     
     
         21  The method as claimed in  claim 17 , including releasing the at least one catch device from the locking ring when the sacrificial material in the at least one fixing degrades. 
     
     
         22  The method as claimed in  claim 17 , wherein the fixing comprises a sacrificial component formed from a sacrificial material and a non-sacrificial component which is less reactive to wellbore conditions than the sacrificial material, and wherein the method includes degrading the sacrificial material in the fixing, and separating the sacrificial material from the non-sacrificial material in the fixing. 
     
     
         23  The method as claimed in  claim 17 , wherein the at least one fixing further comprises a collet and the sacrificial material is a plug inserted into a bore of the collet. 
     
     
         24  A centraliser assembly for use in an oil, gas or water well, the centraliser assembly comprising:
 a centraliser having a body comprising first and second collars, and having a bore with an axis adapted to receive a tubular to be centralised, and at least one resilient device extending between the first and second collars, and 
 a locking ring for receiving the tubular in a position radially inside the resilient device and axially between the first and second collars; 
 the resilient device being resiliently biased in a radial direction away from the locking ring towards a radially extended configuration, and being movable radially relative to the locking ring from the radially extended configuration into a radially restricted configuration in which the resilient device is closer to the locking ring than in the radially extended configuration; 
 the locking ring having at least one catch device adapted to engage with the at least one resilient device in the radially restricted configuration of the resilient device and wherein the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; 
 at least one fixing between the at least one catch device and the locking ring; the at least one fixing comprising a pin adapted to be held in tension perpendicular to the axis of the bore of the body and formed from a soluble sacrificial material adapted to dissolve in wellbore conditions faster than the material of the locking ring or the at least one catch device, and 
 wherein the at least one catch device is adapted to release from the locking ring when the at least one fixing at least partially dissolves, and wherein at least a portion of the at least one catch device is adapted to remain attached to the at least one resilient device when the at least one catch device releases from the locking ring. 
 
     
     
         25  A centraliser assembly for use in an oil, gas or water well, the centraliser assembly comprising:
 a centraliser having a body comprising first and second collars, and having a bore with an axis adapted to receive a tubular to be centralised, and at least one resilient device extending between the first and second collars, and 
 a locking ring for receiving the tubular in a position radially inside the resilient device and axially between the first and second collars; 
 the resilient device being resiliently biased in a radial direction away from the locking ring towards a radially extended configuration, and being movable radially relative to the locking ring from the radially extended configuration into a radially restricted configuration in which the resilient device is closer to the locking ring than in the radially extended configuration; 
 the locking ring having at least one catch device adapted to engage with the at least one resilient device in the radially restricted configuration of the resilient device, 
 wherein the at least one catch device has at least one plate spaced radially from the locking ring which defines a recess radially inside the at least one plate, 
 wherein the recess receives and retains a portion of the at least one resilient device, and 
 wherein the catch device is adapted to resist radial movement of the resilient device away from the locking ring when the catch device is engaged with the resilient device; 
 at least one fixing between the at least one catch device and the locking ring; the at least one fixing comprising a pin adapted to be held in tension perpendicular to the axis of the bore of the body, and formed from a soluble sacrificial material adapted to dissolve in wellbore conditions faster than the material of the locking ring or the at least one catch device; 
 the at least one catch device also incorporating at least one permanent fixing between the at least one catch device and the locking ring; 
 wherein the at least one catch device is adapted to remain attached to the locking ring when the at least one fixing at least partially dissolves, and 
 wherein the at least one catch device is adapted to deform when the at least one fixing at least partially dissolves.