Patent attributes
The invention provides a casing adapter tool which connects and seals to a casing pipe at its lower end and to production or service equipment at its upper end, and is used with well servicing equipment, such as is involved in fracturing. The casing adapter tool includes a generally tubular casing adapter body having an upper end and a lower end, and is formed with a central bore extending therethrough. The central bore provides a profile which forms a casing seal chamber at the lower end, and a barrier seal chamber located thereabove. The barrier seal chamber is formed with a profile to accommodate and seal to a first removable pressure barrier on removal of any well servicing equipment. Most preferably, the barrier seal chamber has a profile sized to provide full bore access to the casing pipe and to accommodate and seal to the first removable pressure barrier which is of a threaded, latched or snap ring type check valve or plug. The casing adapter body may also form a fracturing seal chamber in the central bore above or below the barrier seal chamber, with a profile to permit a fracturing isolation tool to be run in and sealed against the central bore. The casing adapter tool preferably includes a tubing hanger portion at its upper end, such that the tubing hanger can provide a second barrier, such as a check valve. The casing adapter tool thus provides a quick connection, seals and full bore access to the casing pipe. Once all well servicing equipment is removed, the casing adapter tool remains on the well and provides at least one and preferably two independent barriers between the well bore pressure and the atmosphere.