Patents Assigned to Den Norske Stats Oljeselskap
  • Patent number: 5241147
    Abstract: A method and apparatus for heating a transport pipeline by inductive heating. The transport pipeline has a thermal insulator mounted on an outside surface thereof. A pair of parallel extending electric wires without metallic protection, are mounted on an outside surface of the thermal insulator.
    Type: Grant
    Filed: April 30, 1991
    Date of Patent: August 31, 1993
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Carl H. Ahlen
  • Patent number: 5224829
    Abstract: A valve apparatus, in particular a rotatable valve comprising an upper part (10) and a lower part (6) which are demountably attached to each other. The valve's lower part (6) is mainly U-formed with sealing surfaces (17,18) arranged on the outwardly facing side faces, which sealing surfaces, in the case of closed valve bear against at least one valve seat on the valve housing's inlet and/or outlet end, and upper part's (10) external face is designed for totally or partly supporting bearing against lower part's (6) internal face and comprising a passage (34) designed to accommodate equipment, for example controlling or metering instruments in the upper part (10) can, in the case of closed valve, be lifted out of the valve housing (1) for maintenance.
    Type: Grant
    Filed: August 8, 1991
    Date of Patent: July 6, 1993
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Knut V. Horvei
  • Patent number: 5176471
    Abstract: Arrangement for protecting components such as valves and control units incorporated in subsea structures particularly for hydrocarbon production, including a template structure adapted to rest on the sea bed and provided with supporting members for a number of functional modules, each containing at least one of the components, each being adapted to be retrieved to the surface. Each of the modules is provided with at least one fixed roof element and at least one completely removable roof element, these fixed and removable roof elements together covering substantially the entire top area of the module, and the roof elements of all modules in the subsea structure together cover a major portion of the top area of the subsea structure to protect against objects falling from above or moving along the sea bed, such as trawls or the like.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: January 5, 1993
    Assignees: Den norske stats oljeselskap a.s., Mobil Oil Corporation
    Inventors: Peter Frafjord, Bruno Grandgeorge
  • Patent number: 5163510
    Abstract: A method of microbial enhanced oil recovery for recovering oil from an oil-bearing rock formation. A population of aerobic bacteria is introduced into the formation at a position spaced from a production borehole. The micro-organisms are adapted to use oil as a carbon source. Pressurised injection water is introduced into the formation via an injection borehole, the water including a source of oxygen and mineral nutrients. The bacteria multiply using the oil as their main carbon source and the oxygen in the injection water as their main oxygen source. In so doing, they dissociate the oil from the rock formation and the dissociated oil is removed via the production borehole by the injection water.
    Type: Grant
    Filed: February 21, 1991
    Date of Patent: November 17, 1992
    Assignee: Den norske stats oljeselskap a.s.
    Inventor: Egil Sunde
  • Patent number: 5163515
    Abstract: Pumpdown toolstring for performing operations requiring application of power downhole in horizontal or high-deviation oil or gas wells, comprising an elongate toolstring element (30), locomotive devices (31, 32A) on said toolstring element, with at least one locomotive device (32) provided at a trailing or top end of the toolstring element (30). The toolstring element (30) is tubular and has a closed leading or bottom end, whereas it is open at the opposite, top end. The leading locomotive device, (31) adapted to pull the toolstring element during pumping down, has a seal for co-operation with a seat at a no-go or nipple assembly at the bottom end of a tubing from which an extension tubing extend into the horizontal or high-deviation well. The leading locomotive device (31) sealingly surrounds the toolstring element (30) and allows sliding of the toolstring element there-through when engaging the seat.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: November 17, 1992
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventors: Roger Tailby, Joseph L. Pearce, John H. Yonker, Marion D. Kilgore, Ronald K. Churchman, Jack G. Clemens
  • Patent number: 5158141
    Abstract: Interface arrangement for components such as valves and control units incorporated in subsea stations particularly for hydrocarbon production, in which the components during operation are mounted in fixed positions on the subsea station and are adapted to be retrieved therefrom by means of a remotely operated tool unit unit (ROT) havign a mating interface arrangement to cooperate with that of the components. The upper part of the component, which is mounted for retrieval in a substantially vertical direction from its fixed position on the subsea station, is provided with central handling means and one or more coupling members. The handling means and the coupling members are adapted to cooperated with respective mating means and members provided on the ROT. Moreover, the handling means is dimensioned for lifting and transporting the component suspended from the ROT.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: October 27, 1992
    Assignees: Den norske stats oljeselskap a.s, Mobil Oil Corporation
    Inventors: Kenneth C. Saliger, Tormod Hals
  • Patent number: 5158579
    Abstract: The invention relates to a method as well as equipment for smoothing out occurrences of long liquid plugs, so-called slugs, in fluid flows which have more than one phase. The invention is particularly intended for use in transport arrangements for oil and gas, namely multi-phase arrangements for the transport of mixtures of oil and gas. The equipment which is used (termed slug catcher) have amongst other things, a vortex chamber (1) and an overlying pressure tank (2) which temporarily stores oil slugs, and portions them out back into the gas flow so that the load on the transport equipment is smoothened out.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: October 27, 1992
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventor: Conrad Carstensen
  • Patent number: 5154395
    Abstract: In one aspect the invention relates to a ball valve of the type comprising a ball member (83, 85) provided with two axially displaceable sleeves (66A, 66B) adapted to be displaced outwards to sealing engagement against seats provided in the surrounding valve housing (76) in the open position of the valve, so as to form a flow passage (73) through the valve, and which comprises a hollow drive axle for the rotary movement of the ball member between open and closed position and a drive spindle (12, 69) through the hollow drive axle, adapted to bringing about the axial displacement movement of the sleeves. On the drive spindle (69) and for rotation together with it there are provided two preferably disc shaped, first cam members (68A, 68B) on either side of the sleeves (66A, 66B) and the sleeves are provided with corresponding and cooperating second cam members (67A,67B) for the axial displacement by rotation of the drive spindle (69) in relation to the ball member (83, 85).
    Type: Grant
    Filed: July 23, 1991
    Date of Patent: October 13, 1992
    Assignee: Den norske stats oljeselskap a.s
    Inventor: Knut V. Horvei
  • Patent number: 5141056
    Abstract: Injection valve for injecting chemicals into subsurface formations penetrated by an oil or gas well, comprising a cylindrical housing (10) with seals (24A, 24B) for cooperation with well tubing (100), said housing enclosing a cylindrical chamber (1) in which a piston-like sleeve (2) is movable axially so as to cover or uncover one or more radial ports (10A) through a cylindrical wall of said housing (10). A spring (3) normally urge the sleeve (2) to a position in which the ports (10A) are covered. A collet (4) is mounted for axial displacement in a chamber extension (1A) beyond an inner end of the sleeve (2), a compression spring (5) urging the collet against said inner end of the sleeve (2).
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: August 25, 1992
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventor: Roger Tailby
  • Patent number: 5135019
    Abstract: A ball valve for use particularly in subsea hydrocarbon production systems including a valve body having a cavity of generally conical shape and communicating with inlet and outlet ports having a common axis. An insert assembly is provided with a valve ball, two ports corresponding to the inlet and outlet ports, respectively, and associated seat means. The insert assembly has a generally conical shape which is generally the same as that of the cavity and being adapted to be housed therein and to be retrieved therefrom. The insert assembly is composed of two parts joined together generally along a dividing plane. Connector means are provided for releasably fixing the insert assembly in the cavity, and actuator means are provided for rotating the valve ball about its axis between a closed and an open position with respect to said ports.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: August 4, 1992
    Assignees: Den Norske stats Oljeselskap A.S., Mobil Oil Corporation
    Inventor: Pierre Dupont
  • Patent number: 5135050
    Abstract: Device for collecting particulate matter and debris in horizontal or highly-deviated oil or gas wells, comprising a cylindrical housing (10) enclosing a collecting chamber having at least one radial port (7A, B) at a distance from an inner end (5) of said chamber (1), and a piston-like sleeve (3) normally and in a starting position closing said port(s). Releasable means (9) retain said sleeve (3) in said starting position and a spring (8) urges said sleeve (3) towards said starting position. The sleeve (3) has a central axial opening (3D) as well as a differential area (3C) exposed to the pressure outside said chamber (1) in said normal or starting position, whereby upon releasing of said releasable means (9) said outside pressure will move said sleeve (3) towards said inner end (5) of the chamber (1) and open said port(s) (7A, B) so as to collect a quantity of said matter and debris in the chamber.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: August 4, 1992
    Assignee: Den Norske stats Oljeselskap A.S.
    Inventor: Roger Tailby
  • Patent number: 5129417
    Abstract: This invention relates to a valve comprising a valve body and a dismountable closing means. The closing means comprises a closing member and a support which carries the closing member is received in an inner cavity in the valve body. Locking of the closing means in the inner cavity is ensured by means of circular grooves formed in a side wall of the cavity, and movable locking pieces carried by the support and cooperating with an exterior ring via can elements. Axial movement of the ring results in a radial displacement of the locking pieces and thereby permitting insertion and removal of said closing means into and out of said valve body.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: July 14, 1992
    Assignees: Den norske stats oljeselskap a.s., Mobil Oil Corporation
    Inventors: Pierre Dupont, Peter Frafjord, Bruno Grandgeorge
  • Patent number: 5116879
    Abstract: A process for converting synthesis gas, a mixture of hydrogen and carbon monoxide, into a mixture of predominately paraffinic hydrocarbons using a catalyst which includes catalytically active amounts of cobalt and a loading-insensitive second metal selected from the group consisting of platinum, iridium, rhodium and mixtures thereof, composited on an alumnia support. The finished catalyst exhibits a positive x-ray diffraction pattern. A metal oxide promoter may also be added.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: May 26, 1992
    Assignee: Den norske stats oljeselskap A.S.
    Inventors: Sigrid Eri, James G. Goodwin, Jr., George Marcelin, Trygve Riis
  • Patent number: 5112698
    Abstract: A ceramic chromium oxide coating produced by applying a conventional chromium oxide coating to a substrate and wholly or partly fusing the conventional chromium oxide coating by subjecting the chromium oxide coating to laser irradiation. The chromium oxide coating can optionally contain silica and/or alumina and less than 1 percent of metal.The chromium oxide coating can be employed for the internal and/or external protection of components in equipment for production and transport of oil and gas under water.
    Type: Grant
    Filed: September 25, 1990
    Date of Patent: May 12, 1992
    Assignee: Den norske stats oljeselskap a.s
    Inventors: Knut Horvei, Jonas S. Sandved
  • Patent number: 5102851
    Abstract: A catalyst for converting synthesis gas, a mixture of hydrogen and carbon monoxide, into a mixture of predominately paraffinic hydrocarbons. The catalyst includes catalytically active amounts of cobalt and a loading-insensitive second metal selected from the group consisting of platinum, iridium, rhodium and mixtures thereof, composited on an aluminia support. The finished catalyst exhibits a positive x-ray diffraction pattern. A metal oxide promoter may also be added.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: April 7, 1992
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Sigrid Eri, James G. Goodwin, Jr., George Marcelin, Trygve Riis
  • Patent number: 5090479
    Abstract: A method for inhibiting scale formation in oil producing wells. The method comprises pretreating the rock formation of the near well bore area with a surface agent and then a saline solution by injecting these down the well bore. Subsequently the formation is treated with a source of divalent cations such as calcium. An acid inhibitor in the form of a polyacrylic acid derivative, a phosphonated or a phosphinopolycarboxylic acid is then injected into the rock formation and allowed to soak in for a period of 24 hours. The inhibitor is retained on the surface area of the rock formation by means of divalent cationic bonds.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: February 25, 1992
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Peter A. Read, Terje Schmidt
  • Patent number: 5086339
    Abstract: Video system for detection of colored areas on black/white patterned background which comprises a video camera for formation of a set of primary color signals R, G, B and a signal processing unit, which provides information about the recorded area based on a processing of one or more of the signal difference (R-Y), (B-Y), (G-Y) between the primary color signals R, G, B and luminance signal Y. The system can particularly be used for digitalizing of interpreted seismic sections.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: February 4, 1992
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Ingebret Gausland
  • Patent number: 5076732
    Abstract: Procedure for the construction of a concrete shaft for a platform or similar structure, where one of several of the shafts will be outfitted with relatively much equipment. The shafts are constructed of prefabricated sections which are consecutively installed butt-in-butt on top of each other and which are left in the shaft as an internal fully shaped shaft component, as the sections internally contain associated equipment and externally feature bodies for the installation of easily removable formwork elements, preferably easily mountable slipforms, while the space between the formwork elements and a prefabricated section is filled with reinforcement and concrete. The formwork elements, after the hardening of poured concrete, by a per se known procedure, are moved to a higher level.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: December 31, 1991
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Ove T. Gudmestad, John W. A. Coker, Brian L. Stead, Terje A. Warland
  • Patent number: 4988538
    Abstract: A ceramic chromium oxide coating produced by applying a conventional chromium oxide coating to a substrate and wholly or partly fusing the conventional chromium oxide coating by subjecting the chromium oxide coating to laser irradiation. The chromium oxide coating can optionally contain silica and/or alumina and less than 1 percent of metal.The chromium oxide coating can be employed for the internal and/or external protection of components in equipment for production and transport of oil and gas under water.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: January 29, 1991
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Knut Horvei, Jonas S. Sandved
  • Patent number: 4971307
    Abstract: A device for joining of pipelines for transportation of fluids allowing pigs to pass the coupling undisturbed. The diameter of the conduit in the middle portion (II) of the coupling is larger than the nominal internal diameter of the pipelines.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: November 20, 1990
    Assignee: Den Norske Stats Oljeselskap a.s.
    Inventors: Kai Killerud, Arne Vingerhagen, Audun Bratseth