Abstract: Deploying an offshore oil and gas production platform comprises placing a buoyant equipment deck on a buoyant pontoon so that elongated legs on the pontoon, each comprising a buoyant float, extend movably through respective openings in the deck. Chains extending from winches on the deck are reeved through fairleads on the pontoon and connected back to the deck. The chains are tightened to secure the deck to the pontoon for conjoint movement to an offshore location. The chains are loosened and the pontoon and leg floats ballasted so that the pontoon and leg floats sink below the floating deck. The chains are then re-tightened until pawls on the leg floats engage the deck. The buoyancy of at least one of the pontoon and leg floats is increased so that the deck is thereby raised above the surface of the water. The chains are connected to mooring lines around an offshore well site, and the raised deck and submerged pontoon are maintained in a selected position over the site with the winches.

Abstract: The invention is an apparatus, method and system for supporting risers in a floating platform. The apparatus comprises a table disposed above a hull-top surface, a first riser opening in the table, and a first dedicated riser tensioner attached to the table and disposed about the first riser opening. The apparatus further comprises a second riser opening, and a second dedicated riser tensioner attached to the table and disposed about the second riser opening. The method comprises tensioning a first riser with a first dedicated riser tensioner, and tensioning a second riser with a second dedicated riser tensioner, wherein the first dedicated riser tensioner is responsive to the second dedicated riser tensioner. The system comprises a mechanism for tensioning a first and a second riser, wherein the mechanism for tensioning the first riser is responsive to the second riser.

Abstract: An installation for producing oil from an off-shore deposit has a semi-submersible platform, at least one riser connecting the platform to the sea bed, and devices for tensioning the riser. The tensioning devices include, for each riser, at least one submerged float connected to a point on the main run of the riser for hauling it towards the surface, and a mechanism for hauling the riser. The mechanism is installed on the platform and applied to the top end of the riser.

Abstract: A subject of the invention is a ship (20) for recovering petroleum products floating at the surface of the sea, characterized in that it comprises an open front part equipped with a rotary collecting drum (24) which is partially submerged and comprises longitudinal elements (32) that can be moved with respect to the external surface of this drum (24) between two positions, one projecting, one retracted, a hopper (40) situated behind the said drum (24) for recovering the said petroleum products removed by this drum (24), and means (45) for transferring these products from the hopper (40) to at least one settling and storage tank (46). Another subject of the invention is a mobile installation for storing and transporting petroleum products recovered by recovery ships.

Abstract: An installation for producing oil from an off-shore deposit has a semi-submersible platform, at least one riser connecting the platform to the sea bed, and devices for tensioning the riser. The tensioning devices include, for each riser, at least one submerged float connected to a point on the main run of the riser for hauling it towards the surface, and a mechanism for hauling the riser. The mechanism is installed on the platform and applied to the top end of the riser.

Abstract: A method of intervention on the seabed (F) using a free end of one riser (24) originating from a semi-submersible platform (10) designed for producing oil from a deposit, at a number of distinct intervention points (30, 32), includes the following successive steps: tethering the platform (10) to immobilize it in a position floating over the deposit; installing the riser (24) connecting the floating platform (10) to the seabed (F) for intervention at a first intervention point (30); carrying out an intervention at the first intervention point (30); disengaging the free end of the riser (24) from the first intervention point (30), while keeping this end submerged; moving the free end of the riser (24) with respect to the seabed (F) towards a second intervention point (32), while keeping the floating platform (10) in place; and carrying out an intervention at the second intervention point (32).

Abstract: Apparatus for transporting and installing a deck of an offshore oil production comprises a floating barge (10) adapted to support the deck (1) and provided with devices for moving the deck (1). The apparatus includes a support framework (11) for the deck (1) adapted to be placed on the barge (10) and including the devices for moving the deck (1) in the form of at least one rack (21) that can be moved vertically by drive mechanisms (20).