Abstract: There is provided a method of assessing the quality of subsurface position data and wellbore position data, comprising: providing a subsurface position model of a region of the earth including the subsurface position data, wherein each point in the subsurface position model has a quantified positional uncertainty represented through a probability distribution; providing a wellbore position model including the wellbore position data obtained from well-picks from wells in the region, each well-pick corresponding with a geological feature determined by a measurement taken in a well, wherein each point in the wellbore position model has a quantified positional uncertainty represented through a probability distribution; identifying common points, each of which comprises a point in the subsurface position model which corresponds to a well-pick of the wellbore position data; deriving for each common point a local test value representing positional uncertainty: selecting some but not all of the common points and deri

Abstract: Methods, a system and antennas are provided for transmitting or receiving signals from a hydrocarbon production well. The well comprises a well bore formed in a formation, a production liner/tubing extending axially along the well bore, and an inductive coupling disposed around the liner/tubing. The liner tubing is electrically coupled to the formation at two axially separated locations and is electrically isolated from the formation between the locations. For transmitting, an alternating current signal to the inductive coupling to induce a current in the liner/tubing, the liner tubing forming a dipole antenna that generates an electromagnetic radiation signal propagating through the formation. For receiving, the dipole antenna is exposed to an electromagnetic radiation signal propagated through the formation which induces an alternating current signal in the tubing and the current signal is detected at the inductive coupling.

Abstract: One aspect relates to a method of installing a transmission system in a hydrocarbon production well. The transmission system is operable for transmitting power and/or control signals down the well or for transmitting data signals back up the well. The well comprises a main well bore, a production tubing inside the main well bore and a branch off the production tubing. The branch comprises a side track tubing. The method includes: providing a sensor and/or load assembly in the branch; installing a first inductive coupler of an induced current transmission arrangement around the production tubing in the main well bore, and connecting the sensor/load assembly to the first inductive coupler via a communication link. Another aspect relates to a hydrocarbon production well installation.

Abstract: A large diameter subsea gravity separator for ultra deep water conditions of 2000 to more than 4000 m includes a vessel having a shell which defines a cylindrical tubular portion and closure portions at axially both ends of the tubular portion. The shell is a sandwich shell which is dimensioned to provide for a predetermined collapse resistance of at least MPa and includes an inner steel layer, an outer steel layer and a concrete layer completely filling the space between the inner steel layer and the outer steel layer.

Abstract: A centralizer includes a centralizer body to be situated at the outer surface of a pipe string in the form of casing, liner, or the like used while drilling, the centralizer body being formed with a plurality of outer centralizer blades arranged in an inclined manner to the longitudinal axis thereof, wherein the centralizer body has an separate split inner tube secured to the pipe string by means of a press fit, and low friction inner surface of the centralizer body and separate center tube facing each other are made from low friction material.

Abstract: A valve (30) for a production liner (12) in connection with the extraction of oil and gas, arranged to automatically shut of the flow of fluid into the production liner (12) in the event of a gas break-through, whereby the valve (30) comprises a valve seating (32) containing at least one central inflow channel (34) and one or more outflow channels (36, 38) from the valve (30). The valve (30) is constructed with a curved design equal to the shape of the outer diameter of the production liner (12), and is placed on the outside of the production liner (12), and in that a rectangular shut off disk (40) with the same curving is arranged in the valve (30), in the flowing path of the liquid flow, to cause a high velocity flow over the shut off disk's surface (40a) against the valve seat (32), wherein the shut off disk (40) is adapted to seal against said valve seat (32) dependant on the differential pressure being produced by the viscosity of the passing flow.

Abstract: The invention concerns an arrangement for injecting CO2 in a supercritical state into a subterranean geological formation, said arrangement comprising: a conduit having a proximal portion and a distal portion, at least part of said distal portion extending in a substantially horizontal direction; multiple openings being provided in said distal portion of said conduit for injection of CO2 into said geological formation; wherein said multiple openings are provided with outflow limiting means for limiting the flow rate of CO2 through respective said opening into said geological formation. The invention also concerns a method for storage of CO2 by said arrangement.

Abstract: A method of introducing a CO2 composition into an aquifer for storage of CO2 therein, said method comprising injecting CO2 in a supercritical state into said aquifer at one or multiple first vertical positions; and withdrawing brine solution from said aquifer at one or multiple second vertical positions; wherein any one of said first vertical positions is distinct from any one of said second vertical positions is disclosed. An arrangement for introducing a CO2 composition into an aquifer is also disclosed.

Abstract: A CO2 desorption method and equipment for performing this method is described. More specific, a method for desorbing CO2 from an absorption fluid without involving a traditional stripper but instead using a heat exchanger as a flash-tank is disclosed. Further described is the utilization of cooling heat from a condenser for cooling the lean absorbent fluid.

Abstract: A method and a safety device are disclosed for protection of well barrier(s) against excessive bending moments from a riser. The safety device is arranged to detect critical bending loads in or in between the well barrier(s) and/or riser, and may include: a device for detecting changes in a curvature between a load carrying riser pipe and an unloaded stiff body attached to or in the vicinity of the riser pipe, said device for detecting changes in the curvature being arranged to measure a relative distance between the load carrying riser pipe and the unloaded stiff body, and a device for triggering disconnection of a releasable riser connector when the distance between the load carrying riser pipe and the unloaded stiff body reaches a predefined critical distance.

Abstract: A system is provided for passing matter in a flow passage of an oil and/or gas drilling or production installation, in particular for passing trash or drill cuttings in a drilling fluid return line. The system includes at least two valves arranged in series in said passage; and a control device configured to selectively or sequentially actuate said at least two valves, such that the material is allowed to pass said at least two valves in the passage. A method is also provided for passing trash or drill cuttings in a drilling fluid return line.

Abstract: A safety device and method for protection of the integrity of well barrier(s) or other interfacing structure(s) at an end of a riser string or a hose includes a releasable connection in the riser string or hose, the releasable connection arranged to release or disconnect during given predefined conditions in order to protect the well barrier(s) or other interfacing structure(s). The safety device safety device includes at least one sensor to monitor at least one of tension loads, bending loads, internal pressure loads and temperature. The sensor provides measured data relating to at least one of tension loads, bending loads, internal pressure loads and temperature. An electronic processing unit receives and interprets the measured data from the sensor. An electronic, hydraulic or mechanical actuator or switch is arranged to receive a signal from the electronic processing unit and initiate a release or disconnect of the releasable connection.

Abstract: A gate valve is provided for returned drilling mud pressure control and/or well killing. The gate valve includes a flow passage; and a gate member movable for intersecting the flow passage. The gate member includes a gate port which extends from one face to an opposite face of the gate member and is alignable with the flow passage for allowing material in the flow passage to pass through the gate member, and a groove or recess is provided in an inner wall of the gate port, the groove or recess extending from the one face to the opposite face of the gate member. A method is provided for returned drilling mud pressure control and/or well killing, and uses of a gate valve.

Abstract: An oil-in-water monitor cleaning apparatus includes a nozzle configured to direct pressurized cleaning fluid at an optical window.

Abstract: The present invention provides a process for the production of an alkanol (e.g. butanol) comprising converting a carbon source such as a biomass into a carboxylic acid or a derivative thereof using a microorganism, and electrochemically reducing said acid to said alkanol, as well as an apparatus for carrying out said process.

Abstract: A method of estimating a velocity of a geological layer includes providing a first, initial model including an interval velocity associated with a subsurface location and an uncertainty associated with the interval velocity; providing data including an actual or approximated root-mean-square (RMS) velocity associated with a subsurface location and an uncertainty associated with the RMS velocity; and estimating a second model including an interval velocity associated with a subsurface location and an uncertainty associated with the interval velocity, based on the interval velocity and the uncertainty of the first model, and the RMS velocity and the uncertainty of the data.

Abstract: A method for turndown of a liquefied natural gas (LNG) plant, the plant including a liquefaction unit arranged in a flow path of the plant, includes removing LNG from a first location in the flow path downstream of the liquefaction unit; vaporizing the removed LNG, or heating the removed LNG so that the removed LNG is transformed to gas phase; and re-admitting the vaporized or transformed LNG to the flow path at a second location upstream of the liquefaction unit. A corresponding LNG plant is also provided.

Abstract: A method for start-up of a liquefied natural gas (LNG) plant, the plant including a liquefaction unit arranged in a flow path of the plant, including removing LNG from a first location in the flow path downstream of the liquefaction unit; vaporizing the removed LNG, or heating the removed LNG so that the removed LNG is transformed to gas phase; and re-admitting the vaporized or transformed LNG to the flow path at a second location upstream of the liquefaction unit. A corresponding LNG plant is also provided.

Abstract: Disclosed herein is an improved method for reversed flow through a self-adjustable (autonomous) valve or flow control device (2), comprising the step of providing an overpressure on the side of the valve (2) opposite of the side of the inlet (10) exceeding a predetermined biasing force of the resilient member (24) causing lifting of the inner body part (4a) within the outer body part (4b) against said biasing force from a first position of fluid flow between an inner and an outer side of the valve (2) via the flow path (11) and to a second position of reversed fluid flow between said inner and outer side through the second flow path (25). An improved self-adjustable (autonomous) valve or flow control device (2) and use of said improved valve or flow control device are also disclosed.

Abstract: A thermal hydrocarbon recovery apparatus comprises: a plurality of steam injector tubes each provided with a plurality of injector autonomous inflow control devices, AICDs, spaced apart from each other along the length of each steam injector tube; a plurality of production tubes each provided with a plurality of production autonomous inflow control devices, AICDs, spaced apart from each other along the length of each production tube; wherein said injector AICDs are arranged to inject steam into a geological formation so as to reduce the viscosity of hydrocarbons in the formation; and wherein said production AICDs are arranged to permit the flow of heated hydrocarbons into said production tubes for movement to the surface.