Abstract: A method is disclosed for generating a machine learning model to predict a reservoir fluid property, such as gas-oil ratio or density, based on standard mud-gas and petrophysical data. It has been found that this model predicts these reservoir fluid properties with an accuracy that is close to that which can be achieved using advanced mud-gas data. This is advantageous, as than standard mud-gas data and petrophysical data is much more readily available than advanced mud-gas data.

Abstract: A sampling module is for mounting in a pipeline with a multiphase flow meter and for receiving multiphase fluid from the pipeline. The sampling module includes: a separation chamber for receiving and separating a sample volume of fluid from the multiphase fluid, the separation chamber having a vertical extent when in use; a lower valve for opening and closing a lower fluid path between a lower end of the separation chamber and the pipeline; an upper valve for opening and closing an upper fluid path between an upper end of the separation chamber and the pipeline; a lower sensor for measuring fluid properties of the fluid in a lower part of the separation chamber; and an upper sensor for measuring fluid properties of the fluid in an upper part of the separation chamber.

Abstract: A method of estimating a position of a well path within a subsurface formation of the Earth, the method comprising determining a well path estimate using navigation measurements from a downhole tool and a position estimate derived from seismic data. A method of geosteering comprising: estimating a position of the well path and controlling a drill bit in response to the estimated position of the well path to follow a desired well trajectory.

Abstract: A wellhead is provided. The wellhead comprises a high pressure wellhead housing; a casing hanger assembly located within the high pressure wellhead housing; and a casing supported on the casing hanger assembly. The casing hanger assembly is arranged so that the casing is able to move relative to the high pressure wellhead housing. This may be to accommodate well growth experienced by the wellhead during use.

Abstract: A method of conducting a pressure integrity test for an underground formation includes: whilst fluid is supplied to and/or released and returned from the underground formation under pressure, using an automated monitoring and supervisory system to: monitor the pressure of the fluid being supplied to and/or returned from the underground formation in real-time, monitor a volume of the fluid that is supplied to and/or returned from the underground formation in real-time, determine one or more relationship(s) for the monitored pressure and the monitored volume as the pressure and the volume vary relative to each other and/or with time during the real-time monitoring thereof, and analyze the monitored pressure and volume data using the one or more relationship(s) either in real-time or after completion of the pressure integrity test in order to provide information and/or warnings concerning at least one parameter relating to the underground formation.

Abstract: Methods of Enhanced Oil Recovery (EOR) from an oil reservoir by CO2 flooding are disclosed. One method comprises producing a well stream from the reservoir; separating the well stream into a liquid phase and a gas phase with a first gas/liquid separator, wherein the gas phase comprises both CO2 gas and hydrocarbon gas; cooling the gas phase with a first cooler; compressing the gas phase using a first compressor into a compressed stream; mixing the compressed stream with an external source of CO2 to form an injection stream; and injecting the injection stream into the reservoir. Systems for EOR from an oil reservoir by CO2 flooding are also disclosed.

Abstract: A method of plugging a well extending into a formation to facilitate temporary or permanent abandonment of the well. The method comprises conveying a plug placement and verification tool (PPVT) through the well, to a plug formation location, the PPVT comprising a stinger for delivering a plugging material into the well, an expandable packer disposed at one end of the stinger and a pressure sensor disposed below the expandable packer, and operating the expandable packer to form a seal in the well above the pressure sensor. The method further comprises delivering a plugging material from the stinger into a region of the well above the expandable packer, thereby forming a plug in the well, and thereafter creating a pressure change above the plug and verifying the integrity of the plug using the pressure sensor.

Abstract: A method of calculating the temperature of a geological structure is disclosed, wherein there is provided a magnetic parameter of the geological structure. The method includes inverting the magnetic parameter to estimate the temperature of the geological structure.

Abstract: A method of reducing the pressure of a liquid includes the steps of providing a conduit containing a packing material, such that a large number of small passages are formed in the packing material, and passing the liquid through the conduit and the packing material. The amount of packing material through which the liquid flows can be varied to vary the pressure drop experienced by the liquid passing through the packing material. The reduction in pressure achieved may be stepwise (discrete) or continuous. The method may be used to reduce the pressure of an aqueous polymer solution for use in a polymer flood technique for oil extraction, and allows the pressure to be reduced without damage to the polymer.

Abstract: A method for laying a pipeline on a seabed in order to provide controlled thermal expansion includes feeding the pipeline from a pipeline reel through a straightener system; and at the straightener system, imparting an alternating and continuously varying degree of residual curvature on at least a portion of the pipeline.

Abstract: A method of separating fluid phases in a well or riser. The method comprises: locating an inlet device of a flexible tubing at a substantially horizontal portion of the well or riser, wherein a portion of the flexible tubing extends into the well or riser and the flexible tubing terminates at the inlet device; biasing the inlet device against a wall of the well or riser; and extracting a stratified fluid phase from the well or riser through the inlet device and flexible tubing, wherein a shape of the inlet device is configured to match a shape of the wall.

Abstract: A system for liquid surge protection of a subsea riser having a horizontal portion on the seabed and a sag bend portion includes: a flexible tubing having a top end and a bottom end; a plurality of autonomous valves configured to permit liquid to pass through into the flexible tubing, wherein the autonomous valves are arranged between the top end and the bottom end of the tubing; and an inlet device coupled to the bottom end of the flexible tubing, wherein said inlet device is biased against a bottom wall the riser.

Abstract: A hydrocarbon-forming gas compression method comprising: a hydrate formation step in which water and hydrate-forming gas are mixed at a first pressure and a first temperature, resulting in the formation of hydrate; a decomposition step in which the hydrate is warmed, and the hydrate is decomposed to re-generate hydrate-forming gas at a second pressure higher than the first pressure.

Abstract: An offshore oil and gas platform has a power supply system with a cascaded arrangement for a black start. The power supply system includes a first power supply apparatus for providing power at a first energy level, an uninterruptible power supply arrangement configured to receive power from the first power supply apparatus, wherein the uninterruptible power supply is for powering at least one essential and/or safety critical component, and a second power supply apparatus for providing power at a second energy level to a main power distribution system, wherein the second energy level is higher than the first energy level, wherein the second power supply apparatus includes a power source and a high-power energy storage system capable of supplying power at the second energy level, and wherein the second power supply apparatus can receive and store energy from the first power supply apparatus.

Abstract: A method of registering geological data at a formation core tracking system includes, at the tracking system, registering a formation core provided within a field of view of an optical imaging system of the tracking system; tracking the orientation of the formation core relative to the tracking system and the distance of the formation core relative to the tracking system; obtaining data associated with a first section of the formation core which is located at a predetermined distance from the tracking system, displaying the data together with an image of the formation core such that an augmented reality image is provided on a display device of the tracking system, changing the distance between the tracking system and the core; and updating the displayed data by obtaining data associated with a second section of the formation core which is located at said predetermined distance from the tracking system.

Abstract: A system for hydrocarbon production comprising a host for receiving produced hydrocarbon; an offshore hydrocarbon production facility comprising: a production wellhead for connection to a subsea hydrocarbon reservoir; a production platform configured to receive produced fluid from the wellhead and being in fluid communication with the host via a long distance pipeline wherein the wellhead is local to the production platform, and the production platform is configured to process the produced fluid to provide a semi-stable oil product suitable for exporting along the long distance pipeline to the host; wherein the host is configured to store the semi-stable oil product.

Abstract: A suction anchor for a subsea well is provided. The suction anchor includes a wellhead support structure. The wellhead support structure is at least in part external of the internal volume of the suction anchor.

Abstract: A foundation for a subsea assembly is provided. The foundation includes connection points. The connection points permit other components to be connected to the foundation and permit loads to transfer from the other components into the foundation. The foundation may be a suction anchor. A method of converting an exploration well using the foundation to a production well is also provided.

Abstract: A container device for transporting and releasing a plugging material into a well includes a longitudinal chamber for containing the plugging material, the chamber including a tubular wall extending in a longitudinal direction and at least one opening for releasing the plugging material from the chamber; a lower seal extending across the opening and closing the chamber in a closed configuration; a pressure application mechanism provided at an upper portion of the container device for pressurising at least part of the device and expelling the plugging material; and a connector provided at an upper portion of the container device for attaching the container device to an elongate member for lowering into a wellbore.

Abstract: A method of installing or removing a subsea wellhead assembly is provided. The method comprising providing a suction anchor that in use acts as a subsea well foundation, wherein the suction anchor comprises an outer suction skirt; and an inner member, wherein the inner member comprises a high pressure wellhead housing; and installing or removing the suction anchor together with the high pressure wellhead housing on or from a seabed.