METHOD AND APPARATUS FOR SHAPING A WELL HOLE

摘要

A method of shaping a wellbore comprising attaching a drilling apparatus to a drill string, which has a side cutting sub-assembly with both cutting and gauging surfaces; a fluid circulating sub-assembly which has nozzles directing fluid up the wellbore and past the cutting surfaces; and a bullnose assembly with forward pointing nozzles and a bullnosed front end to prevent catching in ledges of a rough drilled wellbore. The drilling apparatus is then passed through the wellbore such that the side cutting sub shears arch wellbore walls of dog legs to ease the turns and smooth the bore wall in preparation for running liner / casing or other down hole assemblies which previously may have had difficulty going in hole.