Sedco, Inc.

Other

Dillard S Hammett

John H Wilson

A self-propelled semi-submersible column stabilized service vessel for tending offshore production and drilling operations is disclosed. The vessel includes a pair of submersible hulls haing ballast compartments for controlling the buoyancy of the hulls. A rectangular service platform which includes fire fighting equipment, rig inspection equipment, repair facilities, and load lifting equipment is supported by means of vertical stability columns which are compartmented and include ballast chambers for controlling the buoyancy of the columns. The fire fighting equipment includes an extendable fire boom for clearing debris and for positioning explosives on the deck of a burning production or drilling platform. An array of monitors is also provided for establishing a curtain of water for thermally shielding the service vessel and for extinguishing a fire on the platform. The rig inspection equipment includes a diving bell and constant tension hoist apparatus for accurately positioning the diving bell along the sloping underwater structure of an offshore production or drilling platform. The load lifting equipment includes a revolving crane which is strategically located on the bow center line of the service platform. The submersible hulls are provided with fixed in-line propulsion units on each hull and variable heading azimuth thrusters disposed near the bow end of each hull. The main propulsion units and variable azimuth thrusters cooperate with anchor lines under constant tension winch control for accurately positioning the service vessel adjacent on offshore production or drilling platform for transferring supplies and equipment or for fire fighting purposes in moderately heavy seas. The buoyancy of the stability columns and hulls is differentially controlled for maintaining stability and trim during heavy load lifting operations. The buoyancy control features are also utilized in combination with davits and constant tension winch assemblies for lifting submerged pipelines for inspection and repair.

Self-propelled semi-submersible service vessel

An apparatus and method for erecting a temporary emergency walkway for personnel between an offshore oil platform and a marine vessel. The disclosed apparatus includes a first walkway attached to the main boom of a crane mounted on the vessel and a second walkway attached to an extendable articulating auxiliary boom. The auxiliary boom, which is normally stored on the deck of the vessel, preferably includes an articulating section having a pair of pivotably connected subsections and an adjoining section which telescopically engages the articulating section. A rapid evacuation of personnel from the platform can be accomplished even in heavy seas by maneuvering the vessel into a position near the endangered platform, attaching the auxiliary boom to the main boom and by appropriate movements of the crane and auxiliary boom placing the end of the auxiliary boom on the platform. After the auxiliary boom has been secured to the deck of the oil platform, personnel can use the walkway so erected to move to a position of safety on the vessel, the emergency crews can move from the service vessel to the platform. The booms also may provide air, hydraulic, and electrical power from the vessel to the platform.

Auxiliary boom for emergency evacuation

Apparatus and method for fire suppression on offshore oil platforms including a stab receptacle on an outer surface of a platform connected to a fluid distribution system within the platform for distributing fire suppressing fluid to selected locations, a stab carrying a fluid conduit from a self-propelled service vessel, with the stab being in turn supported on a boom extending from the service vessel, a pumping system on the service vessel for supplying fire suppressing fluid through the conduit to the stab and thereby to the preselected locations. The service vessel is preferably a semi-submersible and includes a system for dynamic positioning of the vessel such as side thrusters in addition to a main propulsion unit.

Stab water supply system

A system and method for evacuating endangered personnel from an offshore oil platform. The disclosed system includes; a self-propelled marine service vessel equipped with a large capacity revolving crane, a portable evacuation shelter located on the platform and including a single point connecting eye for attaching a recovery line thereto, and a support for the shelter attached to the platform and engaging the shelter from beneath so as to permit the shelter to be lifted vertically from the platform. A rapid evacuation of personnel from the platform can be accomplished even in heavy seas with the disclosed system by maneuvering a marine service vessel into a position near the platform, loading the personnel to be evacuated into the shelter, attaching tension cables from the boom of the crane to the single point connecting eye, while substantially maintaining the service vessel in the standoff position and lifting the shelter from the platform and transporting it to a position of safety on the deck of the service vessel.

Emergency evacuation system for offshore oil platform

A tear-away equipment removal system and method for use in controlling fires on offshore oil platforms. A preferred system includes a stab assembly connected to the end of the tension line and carried by a crane boom on a semi-submersible service vessel. A stab receptacle is provided in an outer wall of an offshore platform and is connected to large equipment units which block access to a fire site. The method includes maneuvering the service vessel and crane to allow connection of the stab assembly to the receptacle and the use of the tension line to physically tear open the outer wall of the structure and to remove the large equipment to provide clear access to the fire site.

Stab system for equipment removal

Blowout containment apparatus for use in offshore areas comprising an inverted funnel adapted for positioning over a wellhead to receive fluids from the well and direct them into a conduit extending from the funnel to surface support and processing equipment. The funnel and conduit are supported from the sea's surface preferably by a vessel such as a barge. The barge carries the equipment to receive the full flow of fluids from the well, to process the fluids, and to conduct the liquids to a nearby tanker where the recovered liquid hydrocarbons may be stored. The method of blowout containment includes the controlled positioning of the support vessel, from which is suspended the inverted funnel, over the wellhead to capture the fluids erupting from the blowout and receiving the fluids from the upper end of the conduit at a rate at least equal to the flow into the funnel end of the conduit.

Subsea blowout containment method and apparatus

A self-propelled semi-submersible column stabilized service vessel for tending offshore production and drilling operations is disclosed. The vessel includes a pair of submersible hulls having ballast compartments for controlling the buoyancy of the hulls. A rectangular service deck or platform which includes fire fighting equipment, rig inspection equipment, repair facilities, and load lifting equipment is supported by means of vertical stability columns which are compartmented and include ballast chambers for controlling the buoyancy of the columns. The fire fighting equipment includes an extendable fire boom for clearing debris and for positioning explosives on the deck of a burning production or drilling platform. An array of monitors is also provided for establishing a curtain of water for thermally shielding the service vessel and for extinguishing a fire on the platform. The rig inspection equipment includes a diving bell and constant tension hoist apparatus for accurately positioning the diving bell along the sloping underwater structure of an offshore production or drilling platform. The load lifting equipment includes a revolving crane which is strategically located on the bow center line of the service platform. The submersible hulls are provided with fixed in-line propulsion units on each hull and variable heading azimuth thrusters disposed near the bow end of each hull. The main propulsion units and variable azimuth thrusters cooperate with anchor lines under constant tension winch control for accurately positioning the service vessel adjacent an offshore production or drilling platform for transferring supplies and equipment or for fire fighting purposes in moderately heavy seas. The buoyancy of the stability columns and hulls is differentially controlled for maintaining stability and trim during heavy load lifting operations. The buoyancy control features are also utilized in combination with davits and constant tension winch assemblies for lifting submerged pipelines for inspection and repair.

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Dallas, TX, United States of America

Dillard S Hammett