REVERSE SLIDING SEAL FOR EXPANDABLE TUBULAR CONNECTIONS

摘要

An expandable threaded connection between segments of expandable tubulars th at provides a high bearing pressure seal at a specific area along the pin and b ox members is disclosed. The invention utilizes a "groove" in a surface of the box memb er and a corresponding "rib" on the pin nose. The radial expansion of the tubulars causes the pin to become shorter in length, thereby causing the pin nose to retract from th e back of the box member. As the pin nose retracts, the rib on the pin nose moves backward until a portion of the rib contacts a portion of the groove in the box member. The point of contact between the rib and the groove creates a metal-to-metal seal between the pin and box members. Because the point of contact between the rib and the groove is a relatively small area, the force acting on the point of contact generates a high bearing pressure that is equal to or greater than the internal pressure within the expandable tubulars and, thus, generates a high pressure seal.