Abstract: A method of completing a well includes lowering a wellhead onto a base at an upper end of the well. A hub with internal threads and an external circumferential stepped recess is secured to external threads of the wellhead. A blowout preventer assembly with an annular locking member having a plurality of locking elements is landed on the hub, and the locking elements are engaged with the recess of the hub. The well is drilled through the blowout preventer assembly to a greater depth then the blowout preventer assembly and the hub are removed. A threaded flange with a plurality of bolt holes spaced around the flange is secured to the external threads of the wellhead and a wellhead member is bolted to the bolt holes of the threaded flange.

Abstract: A wellhead assembly includes a casing head, tubing head, and a production tree mounted on the tubing head. An isolation sleeve is set in a main bore of the wellhead assembly that extends across an interface between the casing and tubing heads so that a portion resides in each. The isolation sleeve is configured so that a fracturing string, and its associated hanger, can be retrieved through the isolation sleeve; which significantly reduces the time and steps required to conduct a fracturing operation in a well. Moreover, the present isolation sleeve can be used without changes to existing casing or tubing heads.

Abstract: A wellhead assembly includes a casing head, tubing head, and a production tree mounted on the tubing head. An isolation sleeve is set in a main bore of the wellhead assembly that extends across an interface between the casing and tubing heads so that a portion resides in each. The isolation sleeve is configured so that a fracturing string, and its associated hanger, can be retrieved through the isolation sleeve; which significantly reduces the time and steps required to conduct a fracturing operation in a well. Moreover, the present isolation sleeve can be used without changes to existing casing or tubing heads.

Abstract: A method of completing a well includes Lowering a wellhead onto a base al as upper end of the well. A hub with internal threads and an external circumferential stepped recess is secured to external threads of the wellhead. A blowout preventer assembly with an annular locking member having a plurality of locking demerits is landed on the hub, and the looking elements are engaged with the recess of the hub. The well is drilled through the blowout preventer assembly to a greater depth then the blowout preventer assembly and the hub are removed. A threaded flange with & plurality of bolt holes spaced around die flange is secured to the external threads of the wellhead and a wellhead member is bolted to the bolt holes of the threaded flange.