Abstract: A floating/tensioned production system for use in deepwater drilling and production operations generally combining a relatively small tension leg platform with a semisubmersible platform. The semisubmersible platform is provided with a working deck supported above the water surface so that an air gap exists between the working deck and the water surface. The tension leg platform provides a heave-restrained production deck for near-surface wellhead equipment. The production deck is supported above the drill site but beneath the water surface by buoyancy members and held in place by one or more tethers. Most other drilling and production equipment is located on the semisubmersible working deck. A caisson, surrounding the production deck, is used to provide a substantially dry working area. In one embodiment, the caisson is retractably attached to the production deck.

Abstract: A remotely controllable tail buoy for use in marine geophysical prospecting operations is disclosed. The tail buoy is attached to the trailing end of one or more seismic streamers towed by the vessel. The tail buoy is provided with rudders that are controlled by a steering mechanism and communication system. The communication system collects and processes radio signals emitted from a radio transmitter located on the towing vessel. The processed signals control the steering mechanism which includes a hydraulic pump for directing fluid into a hydraulic cylinder. The fluid flow rotates the rudders. The tail buoy will travel toward the direction that the rudders are turned and thus avoid hooking or entangling of the tail buoy on other like tail buoys or structures.

Abstract: A drill pipe protector which surrounds and embraces a section of drill pipe. The protector includes at least an outer portion and surface made of an elastomeric material in which a quantity of small, hard particles are interspersed. During drilling operations when the protector is placed in sliding contact with the interior surface of casing in a wellbore, the particles exposed on the protectors surface abrade away rust and other protrusions from the inner surface of the casing to rapidly reduce frictional torque and drag experienced in running the drill string. As particles and elastomer are abraded away, additional particles are exposed. In the preferred embodiment the protector is a sleeve consisting of a pair of semi-cylindrical sections, each having an outer elastomeric layer containing approximately 27% by volume and 43% of the combined weight of substantially spherical glass particles sized in the range of 0.15-0.25 millimeters and having a hardness on the MOH scale of approximately 5.5.