Shell Offshore Inc.

Shell Oil Comapny

William H Petersen

Ray R Ayers

Carl G Langner

James W Stevens

Paul B Ritter, Jr

Robert W Patterson

A tensioning riser system for supporting marine elements such as risers which extend form a fixed lower end at a subsea base or foundation to a moving, floating superstructure. The tensioning system has a lever arm pivotally connected to both the superstructure and the upper end of the marine element and a tension controlling strut member pivotally connected to both the superstructure and the lever arm.

Rocker arm marine tensioning system

A diverless and guidelineless method to connect two subsea flowlines by a jumper assembly is provided. Pivotable stabs and fluid connection means are provided on each end of the jumper assembly. The stabs mate into receptacles located on the subsea flowline connections. The flowline is preferably lowered vertically and hinged over while sequentially landing the two pivotable stabs into their respective stab receptacles.

Subsea wellhead connections

An hydraulic stab sub for use in a remote location that can be inserted into a receptacle with the seals in a retracted position. The seals are expanded to a sealing portion using hydraulic pressure while an hydraulic piston is provided for removing the stab sub from the receptacle.

Hydraulic stab subassembly for remotely operated vehicle vertical

A well valve assembly is disclosed for the control of well fluids that flow in the tubing and the annulus of a well. The well valve assembly consists of two parts, the first part being a housing that forms a portion of the well that has flow openings defined between the tubing and the annulus. The second portion of the well valve apparatus comprises a valve insert that may be lowered down through the well tubing and latched in a position adjacent the housing means. By proper selection and location of seals and flow passages on the valve insert well fluids in the tubing and the annulus may be controlled in a predetermined manner. Since valve inserts having different configurations may be interchanged within the same housing, the well valve assembly may interchangeably direct the flow of fluids within the well.

Well valve assembly method and apparatus

A method and apparatus is set forth in the present invention for supporting the weight of a marine riser by use of a passive tensioning system which utilizes a buoyant member located upon the upper end of the riser. The member has a vertical slot defined through its side such that the riser may access the member from a lateral direction. Such lateral access of the riser to the member allows these buoyant members to be changed from beneath the riser when maintenance and/or inspection is required on a particular member. Since the riser need only to move laterally to access any member, and the riser may be temporarily supported at the surface by other means, the lower end of the riser does not need to be disconnected from subsea equipment when maintenance and/or inspection operations are required on a buoyant member. Well operations do not need to be interrupted, therefore, during buoyant member maintenance operations.

Buoyant member riser tensioner method and apparatus

The present invention provides a method and apparatus for connecting a flowline to a subsea structure. A flowline connection tool is deployed downwardly to the subsea structure and secured to the subsea structure. A flowline terminal head, which is at the end of a flowline, is then pulled toward the flowline connection tool by means of a pull-cable. The flowline terminal head is then secured to the subsea structure and the flowline connection tool is recovered to the surface. The flowline connection tool contains a prime mover means in order to minimize the length of cable exposed to forces encountered in pulling the flowline to the subsea structure.

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Mandeville, LA, United States of America

William H Petersen