Patents Assigned to Den Norske Stats Oljeselskap A.S.
  • Patent number: 7386996
    Abstract: The invention relates to a natural gas liquefaction process and particularly to one suited to use offshore. The invention provides a natural gas liquefaction apparatus wherein a carbon dioxide based pre-cooling circuit is provided in a cascade arrangement with a main cooling circuit. The invention also extends to a natural gas liquefaction apparatus wherein a main cooling circuit uses as a refrigerant a gas stream, at least a portion of which is derived from a raw natural gas source.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: June 17, 2008
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Arne Olay Fredheim, Pentti Paurola
  • Patent number: 6899859
    Abstract: The present invention concerns a method for preparing a CO2-rich gas stream for injection purposes or deposition, and a hydrogen rich gas stream, the method comprising the following steps: a) natural gas and H2O are fed into a one-step reforming process for preparing a gas mixture comprising CO2 and H2 under supercritical condition for water from about 400° C. to about 600° C. and pressure from about 200 to about 500 bar in the reforming reactor; b) the gas mixture from a) is separated into a H2-rich and CO2-rich gas stream, respectively. The invention also comprises use of CO2-rich gas stream for injection into marine formations, and use of H2-rich stream for hydrogenation, as a source of energy/fuel in fuel cells and for production or electricity.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: May 31, 2005
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Ola Olsvik
  • Patent number: 6875358
    Abstract: Method and system for extraction of fat or oil-soluble components, e.g. PAH, NDP and/or BTX, from produced water being separated from an oil or gas plant. The method is characterized by injection of a liquid consisting of hydrocarbons from the oil or gas plant into the water flow, the injection liquid having a lower content of the oil soluble components than the original oil phase in equilibrium with the water, the injection liquid is atomized into the whole water phase and the water/hydrocarbon mixture is given a predetermined retention time thus to allow mass transferring of the oil soluble components from the water to the injection liquid, before the injection liquid is separated from the water in a separator, preferably a hydro cyclone, the injection liquid being adapted to the separators working range for pressure and temperature.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: April 5, 2005
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Eivind Aarebrot, Trygve Håland
  • Patent number: 6838071
    Abstract: The present invention comprises a method for production of a CO2-rich gas stream and a H2-rich gas stream, the method comprising the following steps: a) natural gas and water are fed to a reforming reactor and are converted to synthesis gas under supply of a O2-containing gas: b) the gas stream from a) is shifted, whereby the content of CO is reduced and the amounts of CO2 and H2 are increased by reaction of H2O; c) the gas stream from b) is separated in a separation unit into a CO2-rich and a H2-rich gas stream, respectively. The invention also concerns the use of a CO2-rich gas stream for injection into marine formations, and the use of a H2-rich gas stream for hydrogenation, as a source of energy/fuel in fuel cells or for production of electricity.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: January 4, 2005
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Ola Olsvik, Roger Hansen, Arne Grislingås, Erling Rytter
  • Patent number: 6813564
    Abstract: The invention is a method for monitoring subsidence of the sea-bed (14) of a survey area (8) caused by compaction of an underground hydrocarbon reservoir (1), and comprises the following steps: Conducting at least two series (S1, . . . ,Si, . . . ,Sm) of time-indexed depth measurements (13a, . . . ,13n), with separation in time &Dgr; between the measurement series characteristic of a significantly detectable long-term change of seafloor elevation due to compaction to take place in the reservoir. Measurements are time-indexed and corrected for tidal depth variations. Depth measurements (13) are conducted on survey stations (2) arranged on benchmarks (6) which have settled in the locally consolidated seabed (14). To handle short-term depth variations several stationary time-indexed short-time local reference depth measurement series (19r) are conducted at short-term local reference stations (18r) at benchmarks (6) during each separate measurement series (Si).
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: November 2, 2004
    Assignees: Den Norske Stats Oljeselskap A.S., The Regents of the University of California
    Inventors: Ola Eiken, Mark Zumberge, John Hildebrand
  • Publication number: 20040124842
    Abstract: A system for determining the nature of a subterranean reservoir whose position and geometry is known from previous seismic surveys. An electromagnetic field is applied by a transmitter 18 on the seabed 14 and detected by antennae also on the seabed. The nature of the detected reflected waves is used to determine whether the reservoir contains water or hydrocarbons.
    Type: Application
    Filed: July 22, 2003
    Publication date: July 1, 2004
    Applicant: Den Norske Stats Oljeselskap A.S.
    Inventors: Terje Eidesmo, Svein Ellingsrud, Fan-Nian Kong, Harald Westerdahl, Stale Johansen
  • Patent number: 6735526
    Abstract: A method of combining directional seismic attributes using a supervised learning approach which may include extracting seismic information from acquired data in a direction along the spatial direction of a body of interest. The method is applicable both to onshore and offshore exploration and provides a more reliable means of detecting, separating and identifying geological features, for example gas chimneys, faults, layers, and any other type of geological objects with a spatial direction and shape. The method is also suited for the detection of reservoir changes by the use of time lapse seismic techniques.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: May 11, 2004
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Paul Meldahl, Roar Heggland, P. F. M. De Groot, A. H. Bril
  • Patent number: 6714153
    Abstract: The invention is a well radar for detecting, by electromagnetic wave reflection, resistivity horizons in production zones in oil wells. Transmitter and receiver antennas are combined in a tubing string antenna module. Two dipole transmitter antenna are positioned in a first position on either side of the tubing string antenna module. A first directionally sensitive group of four dipole receiver antennas is positioned in a second positioned so that the receiver antennas have even angular separation. Likewise, a second directionally sensitive group of four dipole receiver antennas is positioned in a third position opposite the first directionally sensitive group.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: March 30, 2004
    Assignees: Den Norske Stats Oljeselskap A.S., Kongsberg Offshore A.S., Norges Geotekniske Institutt
    Inventors: Fan-Nian Kong, Svein Ellingsrud, Vidar Sten-Halvorsen, Einar Stølen, Harald Westerdahl, Terje Eidesmo
  • Patent number: 6700835
    Abstract: Device for subsea metrology of distance and relative orientation of a first termination (10) with a local reference system (xr, yr, zr) and which by means of a jumper spool piece (5) is going to be connected to a separate second termination (20) having a local reference system (xB, yB, zB), characterized by a base metrology unit (2) arranged for being carried by an ROV (4), and arranged for aligned arrangement with the second or the first termination's (20, 10) reference system, and comprising the following features: a wire (3) with an extractable first end (31) being arranged for being attached to a receptacle device (7, 7′) arranged on the termination (10, 20) for receiving the wire's (3) first end (31) or a metrology unit and with a wire tensioner device (32) arranged for tensioning the wire (3) between the base metrology unit (2) and the receptacle device (7, 7′); a wire length sensor (34) arranged for measuring the length (DrB) of the extended taut wire (3); a relative azimuth sensi
    Type: Grant
    Filed: July 23, 2001
    Date of Patent: March 2, 2004
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Nic Ward, Andy Walker, Per Sparrevik
  • Publication number: 20030200030
    Abstract: A method of processing acquired seismic data which comprises extracting seismic information from the acquired data in a direction along the spatial direction of a body of interest thereby producing directional seismic attributes. Any preferred embodiment, the method incorporated unsupervised or supervised learning techniques.
    Type: Application
    Filed: May 9, 2003
    Publication date: October 23, 2003
    Applicant: Den Norske Stats Oljeselskap A.S.
    Inventors: Paul Meldahl, Roar Heggland, P.F.M. De Groot, A. H. Bril
  • Patent number: 6631763
    Abstract: A method and a system for testing a borehole in an underground formation by the use of so-called closed chamber testing. When carrying out the method, a test or production pipe (5) is carried down the borehole, where the test pipe can be closed at its upper end and at its lower end is provided with a downhole assembly (6) comprising equipment for testing of fluid flow from the formation (3), the annulus (23) between the test pipe (5) and a casing (20) in the borehole being shut off during the test by a gasket (22) at a desired depth, and fluid from the formation being allowed to flow through the test pipe (5) to a collecting tank (9) coupled to the test pipe via a flow head (4) at the upper end of the test pipe (5).
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: October 14, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: John Self, Rolf Dirdal
  • Patent number: 6628119
    Abstract: A system for determining the nature of a subterranean reservoir 12 whose position and geometry is known from previous seismic surveys. An electromagnetic field 24, 25, 26, 27 is applied by a transmitter 18 on the seabed 14 and detected by antennea 21, 22, 23 also on the seabed 14. The nature of the detected reflected waves 25, 26, 27 is used to determine whether the reservoir 12 contains water or hydrocarbons.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: September 30, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Terje Eidesmo, Svein Ellingsrud, Fan-Nian Kong, Harald Westerdahl, Stale Johansen
  • Patent number: 6626240
    Abstract: Device for annular isolation in oil/gas wells comprising a production tube, the production tube comprises coaxially positioned, cylindrical sleeve (5) having in one end an at least partially radially directed opening slot (2), said sleeve including a cylindric sealing crown (1) coupled in one end to a release mechanism (3, 4) adapted to push the sealing crown (1) out through the opening, said sealing crown (1) in its other end being expandable in the tangential direction.
    Type: Grant
    Filed: August 16, 2001
    Date of Patent: September 30, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Egil Sunde
  • Patent number: 6607043
    Abstract: A down hole motor assembly includes a hydraulic drive portion, a drill bit operatively connected to the drive portion and a disengage mechanism (11) arranged to disengage drive to the drill bit. The disengage mechanism (11) is arranged to be actuated by supplying drilling fluid to the drive portion at a flow rate which is greater than the flow rate at which fluid is supplied to run the drive portion during normal drilling. The disengage mechanism is arranged to be re-set so that drive is reconnected to the drill bit when the fluid supply to the drive portion is shut off.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: August 19, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Egil Sunde, Per Olaf Haughom
  • Patent number: 6573008
    Abstract: The present invention relates to a cell for the production of electric energy by reaction between hydrogen peroxide or oxygen, and aluminium or lithium or a mixture thereof, and hydroxyl ions in water, where the cathodes are cylindrical and based on radially oriented carbon fibres attached to a stem of metal. The novel feature of the invention is that by utilizing such cathodes in a cell with circulating electrolyte, it is possible to keep the concentration of oxidant in the electrolyte low and thus obtain high utilization of the reactants.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: June 3, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventor: Øistein Hasvold
  • Patent number: 6556014
    Abstract: A device for detecting changes of resistivity or dielectrical properties due to changes of fluid composition in the near-well area about a well in a geological formation, comprising an electrically conductive tubing string, an electrical energy source, a signal generator, at least one transmitting antenna for emitting electromagnetic waves along the tubing string, one or more receiver antennas for receiving electromagnetic waves reflected along the tubing string, devices for receiving signals induced in the receiver antennas, signal processing means for processing the received signals, and communication devices for transmitting signals representing the electrical signals and for receiving control signals.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: April 29, 2003
    Assignees: Den Norske Stats Oljeselskap A.S., Norges Goetekniske Institutt
    Inventors: Fan-Nian Kong, Harald Westerdahl, Terje Eidesmo, Svein Ellingsrud
  • Patent number: 6546962
    Abstract: Air is introduced into the injection water for microbial enhanced oil recovery. The injection water is passed through an ejector where it is entrained and the oxygen subsequently dissolves in the water.
    Type: Grant
    Filed: July 7, 2000
    Date of Patent: April 15, 2003
    Assignee: Den norske Stats oljeselskap A.S.
    Inventor: Egil Sunde
  • Patent number: 6544420
    Abstract: A tube apparatus for outlet of liquid from a container, adapted to receive at least two different fluids with intermediate interface(s), where liquid outlet openings are located above and/or underneath the interface(s). At least one tube member is adapted to have a substantially horizontal position in the container and is provided with at least two liquid outlet openings. A collecting tube communicates with each tube member and serves to lead liquid out of the container. Immediately under and/or over each liquid outlet opening there is provided a plate-shaped flow control element which extends approximately horizontally in all directions with respect to the liquid outlet opening concerned.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: April 8, 2003
    Assignee: Den Norske Stats Oljeselskap A.S.
    Inventors: Jan Høydal, Per Farstad
  • Patent number: 6525540
    Abstract: A method for detecting electrical properties in a geological formation in a well which has within it a tubing string comprising the steps of mounting a transmitter antenna outside of the tubing string in a fixed position with respect to the geological formation, mounting a receiving antenna outside of the tubing string in a fixed position with respect to the geological formation, generating a first series of electromagnetic waves at a first time, receiving a first series of reflected electromagnetic waves in the receiver antenna, transforming the first series of reflected electromagnetic waves to form a first registration, generating a second series of electromagnetic waves at a second time, receiving a second series of reflected electromagnetic waves in the receiver antenna, transforming the second series of reflected electromagnetic waves to form a second registration, and comparing the registrations. Also disclosed is a device for accomplishing the method.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: February 25, 2003
    Assignees: Den Norske Stats Oljeselskap A.S., Norges Geotekniske Institutt
    Inventors: Fan-Nian Kong, Harald Westerdahl, Terje Eidesmo, Svein Ellingsrud
  • Patent number: 6497811
    Abstract: The present invention comprises a composition for reducing the sulphur content in a hydrocarbon composition, wherein the composition comprises a hydrotalcite material, which has been impregnated with a Lewis acid, and optionally a FCC-catalyst. The hydrotalcite material impregnated with the Lewis acid has been added as a separate component, or incorporated in the matrix of the FCC-catalyst. The Lewis acid is selected from the group comprising elements and compounds of the transition metals, and preferably Zn, Cu, Ni, Co, Fe and Mn, most preferably Zn. Further, the Lewis acid may also be selected from the group comprising elements and compounds of the lanthanides and actinides. The present invention also comprises a method for reducing the sulphur content in a hydrocarbon composition. A method for reducing the sulphur content in a hydrocarbon composition, which is to be cracked, is also described.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: December 24, 2002
    Assignee: Den Norske Stat Oljeselskap A.S.
    Inventors: Trond Myrstad, Bente Boe, Erling Rytter, Hege Engan, Avelino Corma, Fernando Rey