Exxon Production Research Company

William D Loth

Joseph A Burkhardt

Martin O Pattison

Darrell G Warner

A structure or template forms a tubular support structure for subsea equipment used in drilling and producing offshore oil and/or gas wells. The template contains production manifolding, remote and safety shut-in control, pump-separator, and pipeline connector subsystems. Certain of the structural tubes are segregated to form compartmented ballast chambers capable of being selectively flooded and dewatered. Certain other structural tubes form piling sleeves. The truss or framework of structural tubes include vertical and horizontal tubes, the latter forming circumferential members as well as interstitial supports. The uppermost of the circumferential members or 'ring' also functions as a fender to protect the equipment within the template. The template is made negatively buoyant upon launch by flooding the compartmented ballast chambers, keelhauled (swung to a position underneath the keel of the drilling vessel), and then lowered to the subsea floor. Once it is positioned on the sea floor the subsea structure is oriented, pile founded and leveled. The template functions as a drilling and casing guide frame ensuring that drilled wells are connectable to the preinstalled manifolding. The template is recoverable by severing the piles and deballasting the compartmented ballast chambers.

Apparatus for anchoring an offshore structure

Subsea structure and method for installing the structure and recovering

Apparatus for use in removing paraffin from a well tubing string above a wireline operated subsurface safety valve assembly installed in the tubing string and its method of operation. The safety valve assembly controls the flow of production oil and/or gas fluids through the tubing string. During normal production operations a wireline connects the paraffin cutting apparatus to surface facilities which include apparatus for maintaining sufficient tension on the wireline to hold the safety valve assembly in open position and for releasing tension on the wireline to permit the safety valve assembly to close. The paraffin cutter apparatus contains means for releasably connecting it to the safety valve assembly. Manipulation of the wireline actuates means on the paraffin cutting apparatus to open an equalizer port in the tubing string. Paraffin cut from the tubing string wall is removed by flow of production fluids through the open equalizer port. Further manipulation of the wireline actuates means on the paraffin cutting apparatus to release the paraffin cutting apparatus from the safety valve assembly and position the paraffin cutting knives or burrs for removal of paraffin from the wall of the tubing string as the paraffin cutting apparatus is withdrawn from the tubing string by means of the wireline.

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Covington, LA, United States of America

William D Loth