Drillable floating equipment and method of eliminating bit trips by using drillable materials for the construction of shoe tracks

摘要

A one trip method for drilling a wellbore below a cemented casing is disclosed. An apparatus for use in performing the method is also disclosed. The method comprises lowering a drill bit into a casing cemented in the wellbore. The casing has float equipment connected therein. The drill bit is rotated in the casing above the float equipment so that it expands radially outwardly to a diameter greater than the inner diameter of the casing. The float equipment, which can be a float shoe or a float collar or any other type of float equipment known in the art, includes an outer case with a valve connected therein. The outer case is comprised of a drillable material. Thus, the drill bit utilized to drill the wellbore can begin its drilling operation above the float equipment and successfully drill a wellbore below the casing having a diameter greater than the inner diameter of the casing.