Blowout preventer spanner joint with emergency disconnect capability

摘要

A spanner joint assembly for connecting between an upper riser and a conventional dual bore tubing hanger in a subsea well. The spanner joint assembly includes upper and lower spanner joint portions connected to each other through an emergency disconnect portion. The upper spanner joint portion has a longitudinal production bore and a longitudinal annulus. The lower spanner joint portion has a longitudinal production bore with a production bore valve and a longitudinal nonconcentric annulus access bore. The emergency disconnect portion includes an upper mandrel connected to the upper spanner joint portion and a lower mandrel connected to the lower spanner joint portion. A releasable mechanical connector includes a retaining groove in the lower mandrel and a collet connected to the upper mandrel. The collet has a latching portion extending beyond the upper mandrel which is adapted to be received in the retaining groove. An actuator sleeve extends around the collet and has a locked position and an unlocked position. The actuator sleeve maintains the collet latching portion in the retaining groove in the locked position and allows the collet latching portion to slide out of the retaining groove in the unlocked position. The production bore valve requires hydraulic pressure to hold it open and the production bore valve fails safe closed when hydraulic pressure is relieved.