Abstract: A frame and system for adding buoyancy to a riser used in connection with floating platforms is provided which, in some example embodiments, includes a stem attached to multiple supports which include flanges arranged to take impact and abrasion loads off an internal buoyancy module. An air management system is also provided.

Abstract: A flexible tubular pipe comprising at least, from the inside outwards, an internal sealing sheath made of a polymer material, a cylindrical pressure vault having an external face and having an internal face placed over the internal sheath. The vault is a winding, in a helix with a short pitch and with a gap between turns, of an interlocked metal profile wire. At least one ply of tensile armour layers is wound with a long pitch. An external protective sealing sheath is made of a polymer. The fastener wire has the same height as the profile wire and is fastened below the neutral fiber of the profile wire. The ratio of the cross section of the profile wire to the cross section of the fastening wire is between 1 and 2 and the ratio of the moment of inertia Iyy of the profile wire to the moment of inertia Iyy of the fastening wire is between 1 and 2.

Abstract: An extendable draft platform, having a deck and buoyancy columns installed in leg wells in the deck for vertical movement from a raised position to a submerged position, includes a connection arrangement for securing the columns to the deck when the columns are in the submerged position. In the connection arrangement, a plurality of first guide elements near the top of each column is engageable by a plurality of complementary second guide elements secured to the deck around each leg well when the column is lowered to its submerged position. A locking mechanism is operable between the columns and the deck when the first guide elements are engaged with the second guide elements. The first and second guide elements may be configured so that the connection between the deck and the columns may be enhanced by over-ballasting the columns and/or by welding the columns to the deck.

Abstract: A frame and system for adding buoyancy to a riser used in connection with floating platforms is provided which, in some example embodiments, includes a stem attached to multiple supports which include flanges arranged to take impact and abrasion loads off an internal buoyancy module. An air management system is also provided.

Abstract: The invention concerns a flexible duct (1) comprising from inside outwards a carcass (2) produced by a short-pitched metallic helical winding forming butt gaps (12), an overlapping layer (10) acting as a heat shield consisting of helically wound plastic strips (10a, 10b), a sealed inner pressure sheath (3), extruded in plastic on said overlapping layer (10), at least an armouring web (5) and at least an outer sealing sheath (7). The invention is characterised in that the overlapping strips (10a, 10b) are wound at a winding angle less than 35°.

Abstract: This process includes the following steps:

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: A process and apparatus for separation of a gas mixture. A process and an installation for cryogenic separation of the constituents of a natural gas under pressure in a first phase separator in which the constituents of each phase are separated in a distillation column. Part of the gaseous fraction from the top of the column is recycled into the highest stage of the column. The process also includes branching of part of a first top fraction from the first phase separator. The process also includes separation of a first bottom fraction from the first separator, in a second separator.

Abstract: A process for the high-yield recovery of ethylene and heavier hydrocarbons from the gas produced by pyrolysis of hydrocarbons in which the liquid products resulting from the fractionated condensation of a cracking gas for the recovery of almost all the ethylene, are supplied to a distillation column, called a de-ethanizer, at different intermediate levels. At the top of the de-ethanizer the vapor of the column distillate is treated directly in an acetylene hydrogenation reactor, the effluent containing virtually no acetylene being separated by a distillation column called a de-methanizer, into an ethylene- and ethane-enriched tail product, while the head product is recycled by compression or treated for subsequent recovery of ethylene.

Abstract: Process for the high-yield recovery of ethylene and heavier hydrocarbons from the gas produced by pyrolysis of hydrocarbons (1) in which the liquid products (12-15, 23) resulting from the fractionated condensation of the cracking gas (1) for the recovery of almost all the ethylene, are supplied to a distillation column (C1), called the de-ethanizer, at different intermediate levels, at the top of which the vapor (31) of the column distillate is treated directly in an acetylene hydrogenation reactor (R1), the effluent containing virtually no acetylene being separated by a distillation column (C2) called the de-methanizer, into an ethylene- and ethane-enriched tail product (43), while the head product (44) is recycled by compression or treated for subsequent recovery of ethylene.

Abstract: A process for liquefaction of and nitrogen extraction from natural gas, an installation for implementation of the process, and gases obtained by this process. In the process, a first top fraction is cooled and liquefied, separated into a second top fraction which is relatively volatile and which provides gaseous nitrogen, and into a second bottom fraction which is withdrawn. The first bottom fraction is cooled in order to provide liquefied natural gas essentially free nitrogen.

Abstract: Process and installation for separation of a gas mixture, and gases obtained by this installation. The present invention pertains to a process and an installation for cryogenic separation of the constituents of a natural gas under pressure (14) by a first phase separator (B1) in which the constituents of each phase are separated in a distillation column (C1). Part of the gaseous fraction (5) from the top of the column (C1) is recycled into the highest stage of the column. The process also includes branching (9) of part of a first top fraction (3) from the first phase separator. The process also includes separation of a first bottom fraction (4) from the first separator, in a second separator (B2). Other modes of embodiment are also described.

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 process and apparatus for the purification of a gas, in particular natural gas, in order to eliminate mercaptans without the use of gas adsorption or cryogenic expansion processes. Natural gas, dried and cooled, is supplied to an absorption column under pressure, producing a head product of a purified gas, and a base product supplied to a fractionating column which separates the most volatile compounds, free from mercaptans, from a gasoline fraction of the natural gas. The mercaptans are eliminated at the head of at least one distillation column, producing a base end product consisting of a mixture of C5 hydrocarbons, heavier than and free from volatile mercaptans, partially mixed with the most volatile recompressed compounds of the natural gas. This mixture is cooled and sent by reflux to the absorption column.

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).

Abstract: An apparatus for reducing the coke dust in the decoking effluents of the hydrocarbon cracking ovens according to the invention provides means for the condensation of the effluent, means for collecting a liquid condensate, means for filtering said liquid condensate, and means for washing the residual vapours and gases that cannot be condensed by using the same condensate suitably filtered from coke, the filtered condensate being evaporated for the following discharge to the atmosphere by using the thermal content of the input decoking gases. A process for reducing the coke dust in the decoking effluents of the hydrocarbon cracking ovens according to the invention consists in that the solid content in the gaseous effluent from the decoking is removed by filtration of the condensate from said gaseous effluent and by washing of gases and vapours contained therein that cannot be condensed.