Patents Assigned to Den Norske Stats Oljeselskap
  • Patent number: 6182763
    Abstract: Subsea unit for offshore production of oil or gas, comprising one or more wellheads with associated christmas trees provided on or at a bottom frame (template). On or at the template there is mounted a swivel device, having fluid connection to the christmas tree or trees and being provided with connection members for risers and an umbilical or control cable from a production vessel at the sea surface.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: February 6, 2001
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Atle Ingebrigtsen, Jørgen Eide
  • Patent number: 6180684
    Abstract: The present invention relates to a process and an integrated plant to be used in the process for the preparation of synthetic fuel (synfuel) and production of electrical energy. A part of the energy produced is used for the operation of the energy requiring steps of the process, whereas the residual part is exported for other purposes. The warm exhaust gas from the part of the plant producing electrical energy is fed to a preheating step for natural gas being used as a starting material for the preparation of synfuel.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: January 30, 2001
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Terje M. Halmo, Alf S. Martinsen, Roger Hansen, Dag Schanke
  • Patent number: 6162105
    Abstract: A two-part vessel for use in oil transport in waters where ice may occur, comprising a first part constituting a barge part having a bow portion and a stern portion and containing a number of loading tanks, the bow portion having a submerged receiving space for a mooring and loading buoy, and a second part constituting a propulsion part having a forward portion and a stern portion which is adapted for breaking ice, the forward portion having a forward end which is adapted for connection to the stern portion of the barge part.
    Type: Grant
    Filed: October 11, 1999
    Date of Patent: December 19, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Kare G. Breivik
  • Patent number: 6155193
    Abstract: A vessel for use in the production and/or storage of hydrocarbons, including a receiving device having a downwardly open space for receiving and releasably securing a submerged buoy connected to at least one riser, a rotatable connector for connection with the buoy and transfer of fluids, and a dynamic positioning system for keeping the vessel at a desired position. The vessel includes a moonpool extending through the hull, and the receiving device is a unit which is arranged in the moonpool for raising and lowering, the rotatable connector being arranged at deck level, for connection to the buoy when the receiving unit with the buoy has been raised to an upper position in the moonpool.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: December 5, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Kare Syvertsen, Per Skiftesvik
  • Patent number: 6109197
    Abstract: This invention relates to a system for loading or unloading a ship at sea, in particular for operations in connection with oil and gas activity, whereby the ship concerned is equipped with a mooring device at its bow. There is included an anchor device located at the seabed, and at least one anchoring line adapted to connect the anchor device to the mooring device on the ship. A permanent anchor device is provided with a swivel device for the anchoring line, and a buoyant body is attached to a middle portion of the anchoring line. Moreover, there is provided a hose connected to the swivel device and to the ship, for loading or unloading operations.
    Type: Grant
    Filed: December 7, 1998
    Date of Patent: August 29, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: K.ang.re Breivik, Arne Smedal, K.ang.re Syvertsen
  • Patent number: 6094937
    Abstract: A method of liquefaction/conditioning of a compressed gas/condensate flow extracted from a petroleum deposit, for transport in liquefied form with a transport vessel, especially for such processing of a compressed gas/condensate flow which has been separated from a crude oil extracted from an offshore oil field. The gas/condensate flow is depressurized and cooled in several steps for producing a stabilized liquefied natural gas (LNG) and a stabilized liquefied petroleum gas (LPG), for transport thereof in separate tanks.
    Type: Grant
    Filed: May 5, 1999
    Date of Patent: August 1, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Pentti Paurola, Sigbj.o slashed.rn Lillesund, Reidar Vik
  • Patent number: 6085680
    Abstract: An apparatus for enhancing the steering effect of ship rudders comprising a rudder with at least one passageway for supplying seawater to ducts in the rudder, and a profile element extending substantially vertically at a leading edge of the rudder and being pivotable about a generally vertical axis, wherein distribution ducts formed between the profile element and the rudder communicate with the passageway and are adjustable so that relative movement of the profile element and the rudder causes seawater to be discharged along the rudder surface facing abaft.
    Type: Grant
    Filed: September 23, 1999
    Date of Patent: July 11, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Arild K. Samuelsen
  • Patent number: 6069179
    Abstract: A method of conducting a continuous multi-phase catalytic reaction such as the conversion of syngas to higher hydrocarbon fuels. Gaseous reactants are introduced via a gas permeable plate into a slurry which includes the product and a finely divided catalyst. The liquid product is separated from the remainder of the slurry by means of a filter unit including a filter member. A pressure differential is established across the filter member by means of a constant level device within the filter unit which maintains a level of filtrate within the filter unit below the level of the slurry. The slurry is maintained in a constant state of agitation by the introduction of the gaseous components as a steam of bubbles. Fluctuations in the pressure differential across the filter member prevent the filter member from clogging, and the gas space is above the filtrate and the slurry are in communication.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: May 30, 2000
    Assignee: Den norske stats oljeselskap AS
    Inventors: Erling Rytter, Petter Lian, Trond Myrstad, Per T. Roterud, Age Solbakken
  • Patent number: 6053787
    Abstract: A rotating coupling device or connector for interconnection between a number of risers (12) suspended from a submerged buoy and a pipe system on a floating vessel for the production of hydrocarbons, comprising a swivel unit consisting of a pair of concentric swivel members (20, 21) in the form of a male member (20) and a female member (21) defining mutually sealed annuluses (22) communicating with associated fluid paths (16) between the topical risers (12) and the pipe system on the vessel. The female member (21) is adapted for non-rotatable attachment to the vessel. The male member comprises a number of axially extending pipes (24) which, at their upper ends are connected to respective annuluses (22) and at their lower ends comprise a releasable connection (25) with fluid paths (16) leading to the respective risers (12).
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: April 25, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Niles Jostein Erstad, K.ang.re Syvertsen
  • Patent number: 6050747
    Abstract: A rotating connector or coupling device for interconnection between at least one fluid passage (9) through a submerged buoy (1, 2) and a pipe system on a floating vessel for the production of hydrocarbons, comprising a pair of cooperating, fluid-transferring swivel members in the form of a female member (3) and a male member (4) which may be introduced axially into or withdrawn from each other, the female member (4) being permanently fixed to the buoy (1, 2), and an electrohydraulic swivel (30) which is arranged on the top of the male swivel member (4) and comprises partly a slip-ring arrangement (37, 45) for the transfer of high electric power and electrical/optical control signals, and partly a number of hydraulic courses for the transfer of hydraulic signals.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: April 18, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Steinar Midttveit
  • Patent number: 6022755
    Abstract: A method of regenerating the catalyst in a Fischer-Tropsch synthesis reaction. Synthesis gas is supplied to the catalyst in conditions which favor high CO conversions. This results in a high H.sub.2 partial pressure which in turn results in catalyst regeneration.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: February 8, 2000
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Keijo J. Kinnari, Dag Schanke
  • Patent number: 5997826
    Abstract: A reactor for catalytic dehydrogenation of dehydrogenatable hydrocarbons, in particular C.sub.3 and/or C.sub.4 hydrocarbons, in a hydrocarbon-containing stream, with selective oxidation of hydrogen. The reactor comprises serially connected in the flow direction of the hydrocarbon-containing stream: a first catalyst zone (2), an oxygen admixing zone (3) provided with a means (5) for separate feeding of an oxygen-containing gas into the hydrocarbon-containing stream, and a second catalyst zone (4). The oxygen admixing zone (3) has a cross section area in the flow direction of the hydrocarbon-containing stream which is from 0.5% to 75% of the cross section area of each of the two catalysts zones (2, 4), so as to obtain a higher flow velocity in the oxygen-admixing zone (3) than in the catalyst zones.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: December 7, 1999
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Rune Lodeng, Pal Soraker
  • Patent number: 5983931
    Abstract: A rotating connector comprising a swivel device (5, 6) having a number of fluid courses (16) for interconnecting a buoy (1) and a pipe system on a floating vessel for production of hydrocarbons, wherein the swivel device comprises a female member (5) and a male member (6) which may be introduced axially into or withdrawn from each other, the female member (5) being permanently fixed to a bottom-anchored centre member of the buoy. One of the fluid courses is arranged for transferring liquefied natural gas (LNG) between the vessel and the transfer line (13) through the buoy, and for this purpose is thermally and physically separated from the other courses.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: November 16, 1999
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Atle B. Ingebrigtsen, Jens R. Odegaard
  • Patent number: 5941325
    Abstract: Pressure converter for mounting above the drill bit at the lower end of a drill pipe for generating a higher fluid pressure in a portion of a drilling fluid flow, including a piston which is moveable in a cylinder. The piston has a large piston area which when moved in a first direction is affected by the pressure of the drilling fluid in the drill pipe, and an opposite small piston area which when moved in the first direction provides an increased pressure in a smaller portion of the drilling fluid flow. A valve arrangement controls the movement of the piston in the cylinder. Conduits communicate with drilling fluid flow passages inside the drill pipe and the annulus outside the drill pipe respectively. The space in front of the small piston area is adapted to receive a particular working fluid and there is provided a moveable membrane so as to separate the working fluid from the drilling fluid.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: August 24, 1999
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Asbj.o slashed.rn B.ae butted.kken, Tore Andersen, Sigmunn Str.o slashed.mm, Jan Skaar
  • Patent number: 5934392
    Abstract: Pressure amplifier mounted at the lower end of a drill pipe for deep drilling to generate an increased fluid pressure. A piston with a pressure stroke and a return stroke between end positions in a cylinder has a large piston area which during the pressure stroke is subjected to the drilling fluid pressure, a first opposite piston area and a second opposite and small piston area which during the pressure stroke generates an increased pressure in a smaller portion of the drilling fluid flow. A valve arrangement controls drilling fluid flows to and from the piston. For each end position of the piston there is provided at least one moveable valve control element which is adapted to be moved by the piston at either end position, in order to activate the valve arrangement.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: August 10, 1999
    Assignee: Den norske stats oljeselskap a.s.
    Inventor: Nils Inge Nilsen
  • Patent number: 5924498
    Abstract: A pressure amplifier can be mounted above a drill bit at the lower end of a drill pipe for generating an increased fluid pressure in a drilling fluid flow to, for example, obtain an increased drilling effect, A reciprocating piston in a cylinder has at one side (a low pressure side) a large piston area and also has a first opposite piston area and a second opposite and relatively small piston area, which generates an increased pressure. A valve device controls drilling fluid flows to and from the piston. Beyond one end of the cylinder there is provided a hydraulic rotary motor adapted to be driven by the pressure difference between the drilling fluid flows in the drill pipe and an annulus. A transmission mechanism converts the rotation of the hydraulic motor into intermittent movements of the valve device between two operative positions.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: July 20, 1999
    Assignee: Den Norske Stats Oljeselskap a.s.
    Inventor: Nils Inge Nilsen
  • Patent number: 5922925
    Abstract: A process for dehydrogenating dehydrogenatable C.sub.2-30 hydrocarbons includes contacting the hydrocarbons under dehydrogenating conditions in one or more reaction zones with a solid catalyst. The solid catalyst includes at least a Group VIII noble metal, a Group IVA metal, and a carrier of a mixed oxide of magnesium and aluminum.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: July 13, 1999
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Duncan Akporiaye, Morten Ronnekleiv, Preben Hasselgard, Age Solbakken, deceased
  • Patent number: 5919739
    Abstract: A plugging liquid for plugging of a zone of a subterranean formation around a drill hole, consisting of an emulsion comprising (a) a continuous phase containing a hydrophobic liquid, an emulsifier and a crosslinking agent for a polysaccharide, and (b) a discontinuous phase containing water and a polysaccharide. A variant of the plugging composition contains in addition a weighting material in the discontinuous phase. Also described is a method for preparing the plugging liquid and a method for plugging a zone of a subterranean formation penetrated by a drill hole in fluid communication with the zone, according to which method the new plugging liquid is injected into the zone via the drill hole and is subjected to high shear forces in the drill hole, whereby the polysaccharide and the crosslinking agent are brought into contact with one another with resulting initiation of a crosslinking of the polysaccharide and the crosslinking agent and a setting of the plugging liquid.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: July 6, 1999
    Assignee: Den norske stats oljeselskap a.s.
    Inventors: Egil Sunde, Hans Konrad Johnsen
  • Patent number: D424447
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: May 9, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Henning Knobel
  • Patent number: D431781
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: October 10, 2000
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Henning Knobel