4254 results about "Ocean bottom" patented technology

A holding member provides for releasably positioning a rotating control head assembly in a subsea housing. The holding member engages an internal formation in the subsea housing to resist movement of the rotating control head assembly relative to the subsea housing. The rotating control head assembly is sealed with the subsea housing when the holding member engages the internal formation. An extendible portion of the holding member assembly extrudes an elastomer between an upper portion and a lower portion of the internal housing to seal the rotating control head assembly with the subsea housing. Pressure relief mechanisms release excess pressure in the subsea housing and a pressure compensation mechanism pressurize bearings in the bearing assembly at a predetermined pressure.

Seabed sensor units, systems including same, and methods for acquiring seabed data are described, one seabed sensor unit comprising a base, the base containing at least one sensor able to detect a seismic signal, electronics comprising a clock and one or more electronic components enabling the sensor to communicate seismic data to one or more memory modules, and a local autonomous power source. This abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

A marine seismic exploration method and system comprised of continuous recording, self-contained ocean bottom pods characterized by low profile casings. An external bumper is provided to promote ocean bottom coupling and prevent fishing net entrapment. Pods are tethered together with flexible, non-rigid, non-conducting cable used to control pod deployment. Pods are deployed and retrieved from a boat deck configured to have a storage system and a handling system to attach pods to cable on-the-fly. The storage system is a juke box configuration of slots wherein individual pods are randomly stored in the slots to permit data extraction, charging, testing and synchronizing without opening the pods. A pod may include an inertial navigation system to determine ocean floor location and a rubidium clock for timing. The system includes mathematical gimballing. The cable may include shear couplings designed to automatically shear apart if a certain level of cable tension is reached.

A sea-floor electromagnetic measurement device for obtaining underwater measurements of earth formations including a central structure and arms attached to the central structure so that they can pivot relative to the central structure. An electrode is attached to the end of each of the arms or to the central structure, and / or magnetometers are attached to the arms. A method for undertaking sea-floor electromagnetic measurements of earth formations including measuring electric fields at a selected distance from a central structure of an electromagnetic measurement system. Magnetic fields are then measured at the same location.

A method for sensing and launching pipeline pigs into a pipeline. The method includes pressurizing a pressure accumulator in a pig launching system that includes a pig chamber, a plurality of pigs, a launch tube, and the pressure accumulator. The method further includes sensing a pressure within the pipeline and applying pressure from the pressure accumulator to force a pig through the launch tube and into the pipeline.

A subsea gas separation system use in drilling an offshore well includes a subsea blowout preventor connected to the well and a gas separator connected to the blowout preventor near the seafloor. Gas released into the well bore during a well control event is removed at the separator and not returned with the drilling mud recirculated to the surface. A method offshore drilling includes a mud circulation circuit established leading down the drill string, through the drill bit, up the borehole, through a subsea pump, and to the surface through a return riser. The subsea pump is protected during critical well control events by removing gas released into the mud at a gas separator located upstream of the subsea pump and in communication with the blowout preventor.

A seismometer having a hydrodynamically efficient shaped body containing a seismic sensor or source, having a propulsion unit located and a control unit for directional control of the propulsion unit for guiding the seismometer to and from an ocean floor. The seismometer can be deployed from a surface ship, helicopter or airplane. The seismometer or surface support vessel contains a navigation unit for directing the control unit to a desired location on the ocean bottom. The apparatus provides a storage device for storing seismic data sensed by the seismic sensor. The navigation system sends a responsive directional command to the apparatus based on the current location and the desired location. Upon arrival at the desired ocean bottom location, the propulsion system acts to couple the apparatus to the ocean floor. A flight control system manages a plurality of the seismometers during navigation to and from the a ocean bottom.

An electromagnetic survey method for surveying an area previously identified as potentially containing a subsea hydrocarbon reservoir, comprising obtaining first and second survey data sets with an electromagnetic source aligned end-on and broadside relative to the same or different receivers. The invention also relates to planning a survey using this method, and to analysis of survey data taken in combination allow the galvanic contribution to the signals collected at the receiver to be contrasted with the inductive effects, and the effects of signal attenuation, which are highly dependent on local properties of the rock formation, overlying water and air at the survey area. This is very important to the success of using electromagnetic surveying for identifying hydrocarbon reserves and distinguishing them from other classes of structure.

A downscan imaging sonar utilizes a linear transducer element to provide improved images of the sea floor and other objects in the water column beneath a vessel. A transducer array may include a plurality of transducer elements and each one of the plurality of transducer elements may include a substantially rectangular shape configured to produce a sonar beam having a beamwidth in a direction parallel to longitudinal length of the transducer elements that is significantly less than a beamwidth of the sonar beam in a direction perpendicular to the longitudinal length of the transducer elements. The plurality of transducer elements may be positioned such that longitudinal lengths of at least two of the plurality of transducer elements are parallel to each other. The plurality of transducer elements may also include at least a first linear transducer element, a second linear transducer element and a third linear transducer element. The first linear transducer element may be positioned within the housing to project sonar pulses from a first side of the housing in a direction substantially perpendicular to a centerline of the housing. The second linear transducer element may be positioned within the housing to lie in a plane with the first linear transducer element and project sonar pulses from a second side of the housing that is substantially opposite of the first side. The third linear transducer element may be positioned within the housing to project sonar pulses in a direction substantially perpendicular to the plane.

A method is disclosed for offshore drilling in which a bit is driven at a far end of a drill string, drilling fluid is injected into the drill string from surface drilling facilities, and drilling fluid passes through the far end of the drill string and flushes the borehole at the bit and entrains cuttings into the drilling fluid which circulates up the casing / drill string annulus. The drilling fluid drawn off near the mudline and is treated through a subsea primary processing stage to removing the cuttings from the drilling fluid. The treated drilling fluid is then returned to the surface with a subsea return pump system and passes to surface drilling facilities for injection and recirculation.

Methods and systems for efficiently acquiring towed streamer marine seismic data are described. One method and system comprises positioning a plurality of source-only tow vessels and one or more source-streamer tow vessels to acquire a wide- and / or full-azimuth seismic survey without need for the spread to repeat a path once traversed. Another method and system allows surveying a sub-sea geologic feature using a marine seismic spread, the spread smartly negotiating at least one turn during the surveying, and shooting and recording during the turn. This abstract is provided to comply with the rules requiring an abstract, allowing a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

A system monitors and controls the injection of additives into formation fluids recovered through a subsea well. The system includes a chemical injection unit and a controller positioned at a remote subsea location. The injection unit uses a pump to supply one or more selected additives from a subsea and / or remote supply unit. The controller operates the pump to control the additive flow rate based on signals provided by sensors measuring a parameter of interest. A one mode system includes a surface facility for supporting the subsea chemical injection and monitoring activities. In one embodiment, the surface facility is an offshore rig that provides power and has a chemical supply that provides additives to one or more injection units. In another embodiment, the surface facility includes a relatively stationary buoy and a mobile service vessel. When needed, the service vessel transfers additives to the chemical injection units via the buoy.

The present invention contemplates implementation of transitory downhole video imaging and / or spectral imaging for the characterization of formation fluid samples in situ, as well as during flow through production tubing, including subsea flow lines, for permanent and / or long term installations. The present invention contemplates various methods and apparatus that facilitate one-time or ongoing downhole fluid characterization by video analysis in real time. The methods and systems may be particularly well suited to permanent and periodic intervention-based operations.

A deepwater windpower plant (DWP) has a tension leg-type floating platform with an evacuable base for adjusting its buoyancy for installation at ocean depths ranging from 40 meters up to 1.5 kilometers and more. The DWP has a typical offshore wind turbine assembled close to shore which is then towed to a desired installation site on the ocean, and held in place by a gravity anchoring base (GAB), to which an evacuable portion or space of the DWP platform is anchored. The GAB has upwardly extending mooring tethers and a power cable which are brought to the ocean surface by attached buoys. The GAB is sunk to the ocean floor at the installation site under controlled conditions so that the GAB lands flat on the ocean floor. As the GAB sinks to the ocean floor, the mooring tethers and power cable are pulled to the surface by their respective buoys. The GAB is loaded with heavy ballast material that can be dropped from barges on the ocean surface into the upwardly open GAB below the barges.

The invention discloses a submarine cable detection underwater robot and an operating method. Mutual switching of a ROV mode and an AUV mode can be achieved by means of a cable security interface, thecapabilities of autonomous navigation, long-distance control and accurate detection are achieved, and the submarine cable detection underwater robot is used for construction exploration, daily routing inspection and failure detection of a submarine cable project. Construction exploration can be conducted on landform of a submarine cable route before the submarine cable project starts, daily inspection is conducted on burying and operation conditions of submarine cables which are put into operation already, and on-site close observation is conducted on the submarine cables being subjected to breaking down or cracking accidents.

A system and method for deploying and / or retrieving a cable underwater. In an embodiment, a system comprises a cage, comprising a guidance system adapted to be remotely operable subsea by a vessel; a communications link operatively linking the guidance system and the vessel; and a non-palletized reel rotatably and removably mounted within the cage, the reel adapted to receive an unspoolable length of cable, the cable comprising two fee ends. In an exemplary method, the reel, onto which cable is spooled is removably and rotatably housed in a cage adapted for remote control use underwater and the cage lowered by a vessel to a position proximate a seafloor. The cage is maneuvered along a predefined flight pattern in substantially a single plane with respect to the seafloor while selectively releasing the cable from the reel. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope of meaning of the claims.

The present invention relates to an improved autonomous node seismic recording device having an integrated modular design and one or more features that assist coupling of the unit to the sea floor in order to improve the vector fidelity of seismic signal measurement.

A method for communicating data in an offshore data communication system comprises measuring L / MWD data with a sensor disposed in a bottomhole assembly positioned in a subsea borehole. The bottomhole assembly is disposed along a drillstring extending through the subsea borehole. In addition, the method comprises communicating the L / MWD data from the bottomhole assembly to the seafloor with a telemetry signal. Further, the method comprises receiving the telemetry signal with at least one telemetry transducer positioned proximal the sea floor. Still further, the method comprises processing the telemetry signal at the seafloor to produce a processed signal. Moreover, the method comprises transmitting the processed signal from the sea floor to the sea surface.

The pig launcher is installed subsea by coupling it to a launcher manifold. The launcher manifold is installed substantially permanently subsea as a part of a pipeline. The pig launcher includes a dual bore collet connector for coupling to the launcher manifold, and a rotary storage magazine for storing the pigs. The launcher manifold can be manufactured, for example, as part of an inline lateral tie-in sled or as part of a pipeline end manifold (PLEM). A branch connection from the pipeline to the pig launcher is provided in the launcher manifold via a piggable Y connection to a dual bore collet connector male hub. The pig launcher is landed and latched to the launcher manifold to complete the pig launching system. A closure valve between the Y connection and the hub prevents a pressure loss when the pig launcher is not installed, and the closure valve is opened to permit passage of the pigs during launching. A throttle valve upstream of the Y connection allows the pipeline pressure to be dropped downstream so that a pig can be launched using upstream pressure. During launching, a kicker valve is opened to bypass the throttle valve and direct the higher upstream pressure through the secondary bore of the dual bore collet connector and into the rotary magazine.

Subsea apparatus and a method for sampling and analysing fluid from a subsea fluid flowline proximate a subsea well is provided, wherein the apparatus comprises at least one housing located in close proximity to said subsea fluid flowline; at least one fluid sampling device located in the housing in fluid communication with a said subsea fluid flowline for obtaining a sample of fluid from the subsea fluid flowline; at least one fluid processing apparatus located in the housing in fluid communication with said subsea fluid flowline for receiving and processing a portion of the fluid flowing through said fluid flowline or in fluid communication with the fluid sampling device, for processing the sample of fluid obtained from the subsea fluid flowline for analysis, while keeping the sample of fluid at subsea conditions; a fluid analysis device located in the housing, the fluid analysis device being in fluid communication with the fluid processing device and / or with the fluid sampling device, the fluid analysis device being used for analysing said sample of fluid or the processed sample of fluid to generate data relating to a plurality of properties of said sample of fluid and communicating said data to a surface data processor or to at least one other subsea apparatus; and conveying means included in the housing for conveying the housing means from one subsea fluid flowline to another subsea fluid flowline or for conveying the housing to the surface.

A subsea well apparatus has features for controlling and monitoring production fluid flow from a well. A Christmas tree lands on a subsea wellhead, the tree having a tubular, open upper end. A first flow passage extends from a lower end of the tree to the upper end for communicating fluid with the well. A second flow passage extends downward from the upper end of the tree and has an outlet on a sidewall of the tree for communicating with a flowline. A production module lands on and is retrievable from the upper end of the tree, the module having a flow loop with one end in communication with the first flow passage and another end in communication with the second flow passage. At least one flow interface device is located in the loop of the production module. The flow interface device may be used to monitor or control the flow and may be a temperature or pressure sensor, a flow or multi-phase flow meter, or a choke.

A method and apparatus for repairing a submerged pipeline. The method comprises installing a pair of hot tap tees on either side of the damaged section of pipeline, cutting a hole in the pipeline through each hot tap tee, inserting and securing plugging pigs into the pipeline, cutting and removing the damaged section of pipeline, and installing a new section of pipeline. The apparatus includes a plugging pig for use during repair of a damaged pipeline comprising a body shaft, a cup seal secured to the body shaft for engaging an interior wall of the pipeline, a cam attached to the exterior of the body shaft, a slip assembly for sliding on the cam and engaging a slip against the pipeline wall, and a control mechanism for engaging and releasing the slip from the wall.

The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly. In another aspect, an apparatus for use in a subsea well is provided. In a further aspect, a method of cutting a casing string in a subsea well is provided.

A method for use in seismic surveying includes determining the shape of a seismic cable during a seismic survey; determining the tension on the seismic cable at a plurality of points along the seismic cable; and predicting a current that will impact the seismic cable from the determined shape and the determined tension. The method may be practiced two-dimensionally in the context of a marine survey employing a towed streamer array or three-dimensionally in the context of laying an array of ocean bottom cables on the seabed. The predicted currents can, in some embodiments; be used to make steering corrections for the seismic cables.

The invention discloses a three-axis test device and methods for sediments including gas hydrates, relating to a testing technology of sediments including gas hydrates. The device is used for making samples with different hydrate contents and uniform distribution by utilizing first circulation and saturation and then cooling of gas-containing saturated water in the samples and then carrying out three-axis shear on the sample in a certain confining pressure so as to determine the mechanical parameters of the samples. Based on the device, a set of methods for testing the three-axis mechanical parameters of the sediments including gas hydrates is formed, and the mechanical parameters measured by the method are closer to the natural state. The device and methods disclosed by the invention are used for carrying out an accurate simulation test on the marine gas hydrate forming process in a laboratory, providing technical assurance and support for the further study of physical and mechanical properties of the marine soil including gas hydrates, and promoting the further development of the research powerfully.

An apparatus and method for removing a subsea structure wherein a housing defining a subsea structure receiving space and having a jetting system attached at or near the bottom of the housing is used to form an excavation around the subsea structure to the desired depth and a frame attached to or mounted in the housing carries a cutter assembly which is movable from a first position on the frame to a second position on the frame, the first position being on one side of the subsea structure, the second position being on the opposite side of the subsea structure.

A system for underwater seismic prospecting or exploration on seafloors, especially deep seafloors, including streamers designed to contain the measurement devices and to lie on the seafloor, in the form of an inner tube that is non-stretching and non-compressible and an outer tube that is extensible to a certain extent. Through the injection of liquid between these two tubes, the buoyancy of each streamers is made positive. This enables it to be detached from the seafloor and towed to the next measuring position.