Abstract: A system (1) for operating a subsea sensor field (2), comprises an automated underwater vehicle—AUV (10) and a subsea service station (13). A sensor (11, 12) in the sensor field (2) comprises a permanently installed base unit (11) and a removable control unit (12). The AUV (10) moves control units (12) to the service station (13) for charging and updating, and then back to the base units.

Abstract: A system (1) for operating a subsea sensor field (2), comprises an automated underwater vehicle-AUV (10) and a subsea service station (13). A sensor (11, 12) in the sensor field (2) comprises a permanently installed base unit (11) and a removable control unit (12). The AUV (10) moves control units (12) to the service station (13) for charging and updating, and then back to the base units. The permanent positions of the base units (11) facilitate time-lapse surveys, and saves energy as heavy equipment may remain on the seafloor.

Abstract: A system (1) for operating a subsea sensor field (2), comprises an automated underwater vehicle—AUV (10) and a subsea service station (13). A sensor (11, 12) in the sensor field (2) comprises a permanently installed base unit (11) and a removable control unit (12). The AUV (10) moves control units (12) to the service station (13) for charging and updating, and then back to the base units.

Abstract: A method for measuring subsidence and/or uprise on a field, comprises the steps of: deploying at least one cable on a solid surface; collecting inline tilt data from numerous tilt sensors deployed along each cable (100); and performing a statistical analysis on the tilt data to determine changes in curvature on the solid surface. Preferably, the statistical method involves computing a cumulative inline and/or cross-line tilt, whereby random errors cancel and systematic changes add. In addition, regression and/or interpolation may provide a quantitative estimate of curvature etc.

Abstract: A system (1) for operating a subsea sensor field (2), comprises an automated underwater vehicle—AUV (10) and a subsea service station (13). A sensor (11, 12) in the sensor field (2) comprises a permanently installed base unit (11) and a removable control unit (12). The AUV (10) moves control units (12) to the service station (13) for charging and updating, and then back to the base units. The permanent positions of the base units (11) facilitate time-lapse surveys, and saves energy as heavy equipment may remain on the seafloor.

Abstract: An apparatus for collecting geophysical information may include a geophysical information station disposed along a seismic communication cable. A bypass circuit responsive to a command signal is in communication with a switching circuit that is operable to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal. An exemplary method for bypassing a geophysical information station in a geophysical information collection system includes sending a command signal to a bypass circuit and activating one or more switching circuits using the bypass circuit to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal.

Abstract: The present invention relates to a system for subsea installation of elongate flexible element, comprising a container for allocating/storing/accommodating an elongate flexible element intended to be installed, said container being positioned on a trenching vehicle arranged to trench said elongate flexible element into the seabed, which container comprises a guide system arranged to control the release of the flexible element, and which trenching vehicle is further linked to a surface vessel via an umbilical cable whereby said vehicle is remotely operable subsea from said surface vessel wherein said guide system comprises a coiling arrangement for keeping the elongate flexible element in a defined coiled configuration inside said container.

Abstract: An apparatus for collecting geophysical information may include a geophysical information station disposed along a seismic communication cable. A bypass circuit responsive to a command signal is in communication with a switching circuit that is operable to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal. An exemplary method for bypassing a geophysical information station in a geophysical information collection system includes sending a command signal to a bypass circuit and activating one or more switching circuits using the bypass circuit to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal.

Abstract: An apparatus for collecting geophysical information may include a geophysical information station disposed along a seismic communication cable. A bypass circuit responsive to a command signal is in communication with a switching circuit that is operable to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal. An exemplary method for bypassing a geophysical information station in a geophysical information collection system includes sending a command signal to a bypass circuit and activating one or more switching circuits using the bypass circuit to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal.

Abstract: To eliminate the risk of damaging an elongate flexible element and/or an accessory integrated therein, such as a seismic cable having sensor modules distributed rather densely along the cable and forming therewith sections that risk being damaged, on passing from a generally horizontal/vertical orientation to a generally vertical/horizontal one during subsea laying or retrieving of the cable, a new direction changing support structure is provided. The support structure comprises at least two rotary sheaves and a rotary support frame for carrying the sheaves, and said at least two sheaves are spaced from each other a distance that is greater than a length of the accessory to permit the element with the integral accessory to extend in a straight line between the two sheaves.

Abstract: The present invention relates to a system for subsea installation of elongate flexible element, comprising a container for allocating/storing/accommodating an elongate flexible element intended to be installed, said container being positioned on a trenching vehicle arranged to trench said elongate flexible element into the seabed, which container comprises a guide system arranged to control the release of the flexible element, and which trenching vehicle is further linked to a surface vessel via an umbilical cable whereby said vehicle is remotely operable subsea from said surface vessel wherein said guide system comprises a coiling arrangement for keeping the elongate flexible element in a defined coiled configuration inside said container.

Abstract: An electrical penetrator for subsea use has an annular cavity between the connector pin and the body of the penetrator that is filled with a dielectric oil which may act as a pressure compensator. In certain embodiments, a plurality of nested boot seals provide a watertight seal between an electrical cable and the body of the penetrator. An inner boot seal has a stepped inner diameter which engages a central, axial, connector pin and at least one wall of a cylindrical projection or an annular recess formed in the external face of the penetrator body. An outer boot seal has a stepped inner diameter which provides a watertight seal to an attached electrical cable, the connector pin and an outer segment of the inner boot seal.

Abstract: A seismic ocean bottom cable array is provided for use in subsurface exploration. The array includes receiver stations for measuring seismic signals, and a cable including conductors for data transmission and an externally attached stress member. The array is assembled during deployment by attaching the data transmission cables and receiver stations to the stress member as it is lowered into the water.

Abstract: An apparatus for collecting geophysical information may include a geophysical information station disposed along a seismic communication cable. A bypass circuit responsive to a command signal is in communication with a switching circuit that is operable to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal. An exemplary method for bypassing a geophysical information station in a geophysical information collection system includes sending a command signal to a bypass circuit and activating one or more switching circuits using the bypass circuit to route electrical power, commands, data or a combination to bypass the geophysical information station in response to the command signal.

Abstract: Provided is a permanent seafloor seismic recording system utilizing Micro Electro-Mechanical Systems seismic sensors. The system includes and expandable backbone, multiple hubs and sensor lines. The sensor lines include multiple sensor modules that include 3-C accelerometers and a hydrophone for providing a 4-C sensor module output signal.

Abstract: Provided is a permanent seafloor seismic recording system utilizing Micro Electro-Mechanical Systems seismic sensors. The system includes and expandable backbone, multiple hubs and sensor lines. The sensor lines include multiple sensor modules that include 3-C accelerometers and a hydrophone for providing a 4-C sensor module output signal.

Abstract: A preferred seismic survey system includes a cable having a sensor unit. The sensor unit includes sensors for detecting acoustical energy (e.g., shear and/or pressure waves) and is disposed in a decoupling device that substantially acoustically uncouples the sensor unit from the cable. One preferred decoupling device includes relatively flexible tension members that isolate the sensor unit from acoustical-energy related movement of the cable. A fastening member, which is optionally formed of vibration absorbing material, affixes the sensor unit to the flexible member. Optionally, a spacer adjusts the resonant frequency of the tension member and a resilient tube encloses the decoupling device. One preferred seismic survey method includes connecting the sensor unit to a cable with a decoupling device that substantially acoustically uncouples the sensor unit from the cable; and positioning a sensor unit on a seabed such that the sensor unit is acoustically coupled to the seabed.

Abstract: A preferred seismic survey system includes a cable having a sensor unit. The sensor unit includes sensors for detecting acoustical energy (e.g., shear and/or pressure waves) and is disposed in a decoupling device that substantially acoustically uncouples the sensor unit from the cable. One preferred decoupling device includes relatively flexible tension members that isolate the sensor unit from acoustical-energy related movement of the cable. A fastening member, which is optionally formed of vibration absorbing material, affixes the sensor unit to the flexible member. Optionally, a spacer adjusts the resonant frequency of the tension member and a resilient tube encloses the decoupling device. One preferred seismic survey method includes connecting the sensor unit to a cable with a decoupling device that substantially acoustically uncouples the sensor unit from the cable; and positioning a sensor unit on a seabed such that the sensor unit is acoustically coupled to the seabed.

Abstract: A seismic ocean bottom cable array is provided for use in subsurface exploration. The array includes receiver stations for measuring seismic signals, and a cable including conductors for data transmission and an externally attached stress member. The array is assembled during deployment by attaching the data transmission cables and receiver stations to the stress member as it is lowered into the water.