Exxon Production Research Company

Thomas G Choate

Richard H Gunderson

Terry N Gardner

James R Barth

A releasable latch-type connector for a tension leg platform tether. A tether portion of the latch is provided with an annularly arranged set of shear lugs. The tether portion of the latch is adapted to be received within a generally cylindrical second portion of the latch. The second portion of the latch is also provided with an annularly arranged set of shear lugs. The two sets of shear lugs are arranged so that the tether portion of the latch may be inserted into the second portion of the latch and then rotated and lifted to cause the two sets of shear lugs to come into abutment, preventing further withdrawal of the tether portion of the latch. This connector is particularly well suited for securing the lower end of a tension leg platform tether to a foundation on the ocean bottom.

Tether connector for a tension leg platform

The present invention relates to a flowline swivel. The swivel is configured so that the product seals are easily replaceable, the included bearing are not exposes to contamination either during use or during replacement of the product seals, and the seal surfaces may be cleaned without disturbing the bearings. The swivel incorporates removable product and environmental seal surfaces.

Flowline swivel with removable product seal surfaces

A seal pressure reduction system for protecting fluid seals located in the sealing gap between the moving parts of a fluid-carrying system from deterioration due to chemical action, excessive temperature or excessive pressure is disclosed. A first seal resistant to chemical action and excessive temperatures is installed in the sealing gap such that the front side of the first seal is in contact with the production fluid. A second seal resistant to excessive pressure is installed in the sealing gap between the first seal and the ambiance to form a sealed cavity along the sealing gap. A hydraulic fluid is located in the sealed cavity. A hydraulic pressure means located between and communicating with the production fluid and the hydraulic fluid is used to pressurize the hydraulic fluid. The hydraulic pressure means is actuated by the pressure of the production fluid to pressurize the hydraulic fluid to a pressure greater than, less than, or equal to that of the production fluid. Thus, the differential pressure acting on the first seal is reduced or eliminated while the second seal is isolated from deterioration induced by the production fluid. In an alternative embodiment, a plurality of second seals are used to form a plurality of sealed cavities between the first seal and the ambiance. Hydraulic fluid is located in each of the sealed cavities. Each sealed cavity has associated therewith a hydraulic pressure means. The initial hydraulic pressure means is actuated by the production fluid to pressurize the hydraulic fluid in the initial sealed cavity. Subsequent hydraulic pressure means are each actuated by the pressure of the hydraulic fluid in the preceding sealed cavity to pressurize the hydraulic fluid in its corresponding sealed cavity.

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Houston, TX, United States of America

Thomas G Choate