High capacity wellhead connector having a single annular piston

Abstract

A wellhead connector for connecting a riser or production tree to a wellhead of a subsea well utilizes a singular annular piston to lock the connector onto the wellhead. The wellhead connector includes a housing that contains dogs for engagement with the exterior of the wellhead housing. A cam ring is also included, which has an inner side for engaging the dogs and moving them inward into a locked position with the wellhead housing. The cam ring is of a reduced proportion relative to prior art. As such, the cam ring outer side is dimensioned to contact the inner side of the connector housing under load. Connecting rods connect the piston to the cam rings. As the piston moves downward, the cam ring also moves downward, forcing the dogs inward into a locked position. As the piston moves upward, the cam ring also moves upward, thereby unlocking the connector. A secondary annular piston is also provided to guarantee unlocking. At preload, a profile on the lower portion of the connector body engages a stepped profile on the outer diameter of the wellhead thereby creating a secondary load path for reacting to the applied bending moment.