WELLHEAD SYSTEM FOR TIEBACK RETRIEVAL

摘要

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.

主权项

1. A wellhead assembly comprising:
a casing head mounted on a wellbore; a tubing head on the casing head; a main bore extending axially through the casing head and the tubing head; a landing area in the main bore that is profiled to selectively receive a fracturing string hanger; and an annular isolation sleeve coaxially set in the main bore and having an inner radius greater than an outer radius of the fracturing string hanger, so that the fracturing string hanger selectively passes through the isolation sleeve.