Patents Assigned to Den Norske Stats Oljeselskap A.S.
  • Patent number: 5492075
    Abstract: A method and a vessel for offshore oil loading, wherein the vessel comprises a number of center tanks (3) arranged in the longitudinal direction of the vessel, and a number of wing tanks (5, 6) located in pairs on either side of respective center tanks, a loading line (19) being connected to the center tanks (3) via respective valves (20), and adjacent center tanks (3) being connected to each other via bulkhead valves (18).
    Type: Grant
    Filed: January 26, 1995
    Date of Patent: February 20, 1996
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Arve Lerstad, Kare Breivik, Trygve G. Egge, Arne Smedal, Ole Overli
  • Patent number: 5464059
    Abstract: There is discussed an apparatus for distributing fluid to at least two separate zones having higher (22) and lower (24) injectivity in a ground formation (10) through a pipe element in a well hole (12), where the pipe element by means of upper and lower sealing bodies (28,30) defines a space (30) which is adjacent to the zone (22) having a higher injectivity and which has a connection (16) to the zone, and where a fluid connection is established between the interior of the pipe element and the space via a replaceable flow pressure-regulating nozzle which establishes a given flow pressure for the current of fluid into the zone (22) having the higher injectivity.
    Type: Grant
    Filed: November 25, 1994
    Date of Patent: November 7, 1995
    Assignee: Den Norske Stats Oljeselskap a.s.
    Inventor: Terje Kristiansen
  • Patent number: 5451384
    Abstract: A process for substantially removing the metal carbonyl content of a gas stream, such as a stream of synthesis gas, by contacting the gas stream with lead oxide, PbO, dispersed upon a support.
    Type: Grant
    Filed: April 23, 1993
    Date of Patent: September 19, 1995
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Norman L. Carr
  • Patent number: 5442590
    Abstract: The device comprises instruments for collection and recording of signals in seismic exploration of the substratum off-shore. The device is designed as a pole which is adapted to be forced down into the seabed and comprises a pointed lower end (7), an intermediate approximately cylindrically shaped main portion (6), a vibration-absorbing spacer (14) between the pointed end (7) and the intermediate main portion (6). The other end of the intermediate main portion (6) is connected to a top part (8) designed for inserting/pulling and other ways of handling the device. The pointed end (7) at least comprises geophones (15-17) and a hydrophone (23) is placed in the vicinity of the upper end of the device. The majority of the device's other instruments are placed in the intermediate main portion (6). The device is connected to a main cable (4) which extends to a seismic ship (29, 31).
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: August 15, 1995
    Assignee: Den norske stats oljeselskap a.s
    Inventors: Bjornar Svenning, Eivind Berg
  • Patent number: 5413310
    Abstract: Valve, in particular large ball valve for use in oil and gas installations, of the kind comprising a valve member (2) having a through flow passage (6), a movable seat or seal holder (8, 9) and means (11, 12) for moving the holder in directions towards and from cooperating parts (21, 22) of the valve member. At least one opening from the flow passage (6) is surrounded by a protruding edge portion (20) provided with an annular sealing surface (21). A front portion (17) of the seat or seal holder (8, 9) also has an annular sealing surface (18) adapted to cooperate with the sealing surface (21) on the valve member (21) in the open position thereof (FIG. 1B). Outwardly of its sealing surface (18) the front portion (17) has a seal member (19) adapted to cooperate with a second sealing surface (22) on the valve member (2) in the closed position thereof (FIG. 1A).
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 9, 1995
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventor: Knut V. Horvei
  • Patent number: 5395491
    Abstract: This invention relates to a method and means for preventing or greatly reducing biological growth on the cathode (7, 11) of a sea water cell (1) which is based on electrolytic reaction between oxygen, water and a metal anode (6, 10), and which is arranged to be connected to a load (3, 15) through a DC/DC converter (2, 14). An external power supply (5, 16) which may be powered from the load (3, 15), is at intervals connected to an electrode of copper (or copper alloy) (8, 12) included with the cell structure, to electrolytically dissolve copper. The negative terminal (18) of the power supply (16) may at intervals be connected to an auxiliary electrode (13) of a suitable metal or metal alloy such as copper, titanium or stainless steel. The interconnection of the power supply (5, 16) to the electrode (8, 12), and possibly to the auxiliary electrode (13) is controlled by a timing device (4, 17). At intervals, the same or a separate timing device (4, 17) may turn-off/switch-on the DC/DC converter (2, 14).
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: March 7, 1995
    Assignee: Den norske stats oljeselskap a.s.
    Inventor: Oistein Hasvold
  • Patent number: 5390739
    Abstract: Hydraulic tool for carrying out relative axial movements in an oil or gas well by means of hydraulic pressure through a hollow tubing string, comprising a cylindrical tool housing and axially movable cylinder-piston members in the housing. There are provided concentric, hollow cylinders (20,30) each being separately movable axially in said housing (10), and an inner piston (40) being axially movable within an adjacent cylinder (30). Breakable retaining elements (31,32) keep said inner piston (40) and said adjacent cylinder (30) in an initial position until said retaining elements are overcome by the hydraulic pressure. Thrust dogs (21,22) cooperate with recesses (88) in a surrounding tubing component (80) where axial movement of said outer cylinder (20) causes radial expansion of said thrust dogs (21,22), by means of conical surfaces (23) on said outer cylinder (20).
    Type: Grant
    Filed: May 11, 1993
    Date of Patent: February 21, 1995
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventor: Roger Tailby
  • Patent number: 5375671
    Abstract: Converter group comprising at least two pressure converters adapted to be mounted in a row axially above the drill bit at the lower end of a drill pipe for deep drilling, in particular for oil and gas, and for generating an increased fluid pressure utilizing energy in a drilling fluid flow down through the drill pipe, so as to obtain an enhanced drilling effect, preferably by means of one or more high pressure jets adapted to have a cutting action in a surrounding rock formation. Pressure converters (20A, 20B) have axially abutting end faces (22A, 22B) of spherical shape. Attachment means for axial interconnection of the pressure converters are resilient or flexible so as to make possible a certain, small freedom of angular movement between the axes of the pressure converters.
    Type: Grant
    Filed: October 27, 1993
    Date of Patent: December 27, 1994
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Knut V. Horvei
  • Patent number: 5361857
    Abstract: A pressure converter for deep drilling keeps contaminated drill mud outside of the working mechanisms of the drill fluid. Thus, the inner drill mechanisms are kept clean by drill fluid. The device contains a rotatable valve positioned above the controlling piston. A tap cover, containing the valve, has two diametrically opposed inlets and two diametrically opposed outlets. The valve has a through passage which is connected to the inlets when the valve is in a second position. Thus, when the piston is operating in a return fashion, the drilling fluid is provided to the area beneath the piston head, keeping this area clean of drill mud.
    Type: Grant
    Filed: September 7, 1993
    Date of Patent: November 8, 1994
    Assignee: Den Norske Stats Oljeselskap a.s.
    Inventor: Knut V. Horvei
  • Patent number: 5337819
    Abstract: Washing tool for removing internal deposits in tubing parts and components in wells for oil or gas production, wherein the tool is to be run on coiled tubing and to be operated by fluid pressure. The tool comprises a main body (10) provided with discharge nozzles for discharging a washing fluid, and a valve member (12) which is axially movable within the main body (10) under pressure actuation and against a spring force (24), for opening one or more of the discharge nozzles. An external valve member (14) at an upper portion of the main body (10) is arranged for axial movement against the action of a spring (15A) urging the external valve member towards a position for blocking the fluid pressure from above.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: August 16, 1994
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Roger Tailby
  • Patent number: 5337596
    Abstract: Apparatus for measuring permeability in rock samples comprising a measuring table (1, 41) for strapping down a rock sample (2), a nozzle (18) that can be pressed against the rock sample (2) at a set force, a gas source (23) connected to the nozzle (18), devices (24) for measuring mass flow through the nozzle and pressure in the nozzle. The apparatus comprises a rack (10,48) equipped with a pneumatic cylinder to which the nozzle is attached and where the rack and measuring table are movable in relation to each other in an X and Y direction via motors. A computer (21) that controls: (a) the motors, and thereby the movements of the nozzle and the measuring table relatively to each other so that the sample is covered by a predetermined measuring point pattern, (b) a mass flow meter (24) that controls and measures the gas flow to the nozzles, (c) a selector valve for compressed air that controls the pneumatic cylinder, and thereby the vertical movement of the nozzle.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: August 16, 1994
    Assignee: Den Norske Stats Oljeselskap A.S
    Inventors: Christian Halvorsen, Jr., Andrew R. Hurst
  • Patent number: 5265066
    Abstract: A marine seismic seabed cable for use on or near the seabed includes at least one pulling cable, a data cable, and a sleeve which surrounds the data cable and the pulling cable. Groups of geophones and position metering instruments are placed along the cable with the position metering instruments and geophones being disposed in a geophone sphere. The geophone sphere and the pulling cables are to a substantial degree mechanically isolated from each other so that, for example, shocks and signals against the seabed cable will only be transferred to a minor extent to the geophone sphere.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: November 23, 1993
    Assignee: Den norske stats oljeselskap a.s
    Inventors: Bjornar Svenning, Eivind Berg
  • Patent number: 5253223
    Abstract: A device including instruments for use on the seabed for the collection and recording of first signals during off-shore seismic exploration.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: October 12, 1993
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Bjornar Svenning, Eivind Berg
  • Patent number: 5246080
    Abstract: A pressure converter for a drill pipe includes a housing with a header channel therein which is in communication with a drill bit, a drive unit which is driven by a driving drilling fluid flow of the drill pipe, a valve which is operatively connected to and moved by the drive unit, a piston which moves in a reciprocating manner thereby creating a pressure stroke and a return stroke, and a check valve through which a portion of the drilling fluid flow is discharged to the drill bit via the header channel.
    Type: Grant
    Filed: May 6, 1992
    Date of Patent: September 21, 1993
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Kunt Horvei, Idar G. Johnsen
  • 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