GEORGE F DAVENPORT III
Engineers in Houston, TX

5037241, Aug 6, 1991

Mar 29, 1990

7/501597

Stephen D. Vaughn - Houston TX
George F. Davenport - Houston TX
Ray L. Steinmetz - Houston TX

Exxon Production Research Company - Houston TX

E02D 2500

405209

An improved apparatus is disclosed for setting a deck structure or other marine superstructure using a barge mounted cantilevered support structure. The cantilevered support structure is attached at one end of a floating vessel. The cantilevered support structure extends past the edge of the vessel and, in one embodiment, includes means for rotating parallel support members about the deck of the floating vessel permitting the cantilevered support structure to be raised and lowered while it remains substantially parallel with the top of the offshore platform enabling the superstructure to engage the top of a previously installed offshore platform in a synchronized manner. Alternatively, this superstructure may be aligned directly over the platform. A cantilevered drilling rig is then aligned over the cantilevered support structure and used to lift the deck structure or marine superstructure, permitting the vessel and cantilevered support structure to move. The drilling rig is then used to lower the marine superstructure onto the top of the previously installed offshore platform.

4696601, Sep 29, 1987

Jul 14, 1986

6/885358

George F. Davenport - Houston TX

Exxon Production Research Company - Houston TX

E02B 1700

405202

An articulated, compliant offshore structure having a base portion establishing a gravity-type foundation on the ocean bottom, a tower extending upward from the base portion and a deck seated on the tower a spaced distance above the ocean surface. The tower is secured to the base portion by an articulated joint which permits the tower and deck to undergo limited pivoting about the base. This provides compliancy in response to forces imposed on the structure by wind, waves and ocean currents. A set of tensioned members, preferably cables, are secured between anchorages on the base and at an elevated position on the tower to provide controlled resistance to pivoting of the tower. In the preferred embodiment the tower and base are concrete shell structures.

4810135, Mar 7, 1989

Jun 4, 1987

7/058020

George F. Davenport - Houston TX
Lyle D. Finn - Houston TX
Jerome Q. Burns - San Diego CA

Exxon Production Research Company - Houston TX

E02B 1700

405224

A compliant offshore structure in which the primary restoring force to lateral displacement is provided by elongate flex elements. A gravity base is rigidly secured to the ocean bottom. A tower extends vertically upward from the base to a position above the ocean surface. A work deck is supported atop the tower. The tower is secured to the base by elongate flex elements which are arranged in an array surrounding the central axis of the structure. Each flex element has one end secured to the base and a second end secured to the tower. The flex elements permit the tower to pivot about its lower end, thus providing the tower and deck with a compliant response to environmental forces. The flex elements also support the tower above and free from contact with the base. This eliminates the need for a vertical load bearing joint between the tower and base.