| CPC E21B 37/00 (2013.01) [E21B 23/01 (2013.01); E21B 29/10 (2013.01); E21B 33/124 (2013.01); E21B 33/14 (2013.01); E21B 43/10 (2013.01); E21B 29/002 (2013.01)] | 6 Claims |

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1. A process for remediating a well having a restriction caused by inward deformation of a well casing or liner, the process comprising:
a) passing down the well a milling tool and milling away casing or liner in a region of the restriction such that rock surrounding the casing or liner is exposed and such that the casing or liner is divided into an upper and a lower portion each having an open end;
b) performing an under-reaming operation to ream away rock and/or cement in a region between the upper and lower portions of liner or casing;
c) performing a wash operation to remove loose rock, cement and/or metal swarf from a pre-existing void in the rock surrounding the casing or liner;
d) passing down the well a straddle joint;
e) locating upper and lower ends of the straddle joint in the upper and lower portions of casing or liner;
f) after placement of the straddle joint, injecting cement or other settable medium outwardly through a port in the straddle joint into the pre-existing void in the rock surrounding the casing or liner;
wherein said inward deformation creates a pre-existing void in the rock adjacent the restriction in the casing or liner,
wherein the cement or other settable medium enters and substantially fills the pre-existing void adjacent the exterior of the straddle joint, thereby supporting against collapse of the rock.
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