Mcdermott International, Inc.

J. Ray Mcdermott, S.a.

Gary E Harrison

Stephen T McCoy

David A Gray

A pipeline branch arrangement that forms a piggable-Y at the intersection with the trunkline and is oriented vertically relative to the trunkline. The approach piping to all legs of the piggable-Y are configured to incorporate 3D bend or larger radii as required. This arrangement permits the passage of foam pigs, hard pigs, and smart pigs. Rotation of the piggable-Y to the vertical plane configures all of the branch piping in the vertical plane, which permits the support sled width for pipe laying to be kept to a minimum. The arrangement of the 3D bends fore and aft of the piggable-Y aligns the trunkline ends in a co-linear manner. This permits the configuration to be installed by conventional S-Lay techniques.

Pipeline branch arrangement

A method of laying pipeline in water greater than 1000 feet deep is disclosed whereby the pipeline is assembled on board a lay barge and then, during deployment, is bent beyond typical elastic bending limitations and Conventional Lay bending strain limitations while passing along a stinger where it is subsequently reverse bent to remove any permanent curvature. Upon further deployment, a generally horizontal axial load is maintained on the pipeline as it come to rest upon the sea floor such that the final in-situ residual bending curvature of the pipeline is nearly zero or falls within an acceptable range.

Method of deepwater pipelay

A method of locally supplying slack to an axially tensioned length of pipeline spanning unsupported across an undulating seabed. During pipeline deployment, the pipeline is fitted with two weighted masses that will be positioned on either side of the undulation to be spanned. These masses will be spaced a predetermined distance from each other along the seabed, this distance being less than that between them along the pipeline. Also during deployment, the mid-region of this span is vertically deflected upward while retaining the axial tension in the pipeline. Once the pipeline is properly positioned, the vertical deflection of the pipeline is reduced thereby relieving the axial tension in the pipeline while also introducing sufficient pipeline slack such that the pipeline can closely follow the contours of the undulating seabed.

Growing community of inventors

Katy, TX, United States of America

Gary E Harrison