Patent ID: 6196336
Filing Date: 2001-03-06
Classification: E21B

Abstract:
A drilling liner system for use in continued drilling of a borehole having a casing therein, the casing having a drilling tubular inside and a liner hanger/packer assembly at the bottom, the drilling liner system comprising:(a) a tubular coupled to the drilling tubular and to an inner bottom hole assembly, the inner bottom hole assembly including:(i) a drilling motor coupled to the tubular and adapted to be operated by mud conveyed by said tubular; and(ii) a drive shaft on the drilling motor coupled to a male sub with retractable drive splines thereon, the male sub coupled to a pilot bit for drilling a pilot hole upon operation of the drilling motor; and(b) a liner coupled at a first end to the liner hanger/packer and at a second end to an outer bottom hole assembly, the outer bottom hole assembly including:(i) a female sub adapted to engage drive splines on the male sub and rotate with the male sub upon being engaged thereto, and(ii) a core bit surrounding the pilot bit and coupled to the female sub for drilling an enlarged hole.