PROTECTION OF CASING LOWSIDE WHILE MILLING CASING EXIT

摘要

The lowside of a casing joint is protected from wear while milling a casing exit for a lateral borehole. The casing joint is coupled to a casing string and is made of a material that is softer than that of the casing string. A whipstock assembly is arranged within the casing joint and has a deflector surface operable to direct a drilling assembly into a sidewall of the casing joint to create the casing exit. A wear sleeve is coupled to and extends axially from the whipstock assembly, the wear sleeve defining a throat that extends axially along the axial length of the wear sleeve and transitions into the deflector surface. The axial length of the wear sleeve extends beyond a point of contact where the drilling assembly would otherwise engage the lowside of the casing joint.

主权项

1. A well system subassembly, comprising:
a casing joint coupled to a casing string and defining a lowside therein, the casing joint being made of a first material that is softer than that of the casing string; a whipstock assembly arranged within the casing joint and having a deflector surface operable to direct a drilling assembly into a sidewall of the casing joint to create a casing exit; and a wear sleeve coupled to and extending axially from the whipstock assembly, the wear sleeve defining a throat that extends along an axial length of the wear sleeve and transitions into the deflector surface, wherein the axial length of the wear sleeve extends across a point of contact where the drilling assembly would otherwise engage the lowside of the casing joint, whereby the wear sleeve protects the lowside of the casing joint from wear caused by the drilling assembly.