Abstract: A tubing suspension system for undersea well production operations employs a nonoriented tubing hanger having an inner body for supporting a tubing string and a landing collar for supporting the tubing hanger on a wellhead casing. The tubing hanger includes three cooperating concentric sleeve assemblies which are employed to lock and seal the tubing hanger to the wellhead housing. The outer sleeve assembly includes a locking actuator and a dual seal assembly and is separately retrievable from the remainder of the hanger assembly. A nonorienting hydraulic set running tool is employed to run the tubing hanger, set the seals, lock the tubing hanger to the wellhead casing, retrieve either the outer sleeve assembly or the entire tubing hanger. The running tool includes a hydraulically controlled actuating sleeve which carries a latch dog assembly which locks with the tubing hanger.

Abstract: This invention relates to methods and apparatus for monitoring fluid pressure in a subsea petroleum installation or other similarly inaccessible system while isolating the well fluid from the production control system. In one particular form of the invention, a body of secondary fluid is pressure-responsively coupled to but isolated from the oil or other primary fluid of interest by a piston, which subjects the secondary fluid to the pressure existing on the primary fluid. In addition, a measuring device is connected to the secondary fluid to derive an electrical signal representation of the pressure on the secondary fluid as a correlative indication of the wellhead or other pressure actually sought to be measured.