Abstract:
The present invention relates to streamer cables. One embodiment of the present invention relates to a method for preparing a streamer cable. The method may comprise retrofitting the streamer cable with a solid void-filler material, where the streamer cable was configured as a liquid-filled streamer cable. The retrofitting may comprise introducing a void-filler material into the streamer cable when the void-filler material is in a liquid state and curing or otherwise solidifying the void-filler material to a solid state. In another embodiment, the present invention relates to a streamer cable comprising an outer skin and-at least one sensor positioned within the outer skin. The streamer cable may also comprise a solid void-filler material positioned between the outer skin and the at least one sensor, wherein the solid void-filler material is coupled to the at least one sensor.
Abstract:
A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of and disposed inside the jacket. At least one seismic sensor is mounted in a housing affixed to the at least one strength member. A void filling material fills the interstices inside the jacket. The housing is configured to isolate the at least one sensor from pressure variations in the void filling material, and the housing is configured to couple the at least one sensor to a body of water outside the streamer.
Abstract:
A method and apparatus for a seismic cable is described. The apparatus includes a plurality of cable segments comprising at least a first cable segment and a second cable segment coupled by a connector. The connector comprises a cylindrical body having a first diameter, a portion of the body having a second diameter that is smaller than the first diameter and centrally positioned between opposing ends of the body, a first coupling section having a terminating end of the first cable segment anchored therein, and a second coupling section having a terminating end of the second cable segment anchored therein, at least a portion of the first and second coupling sections being rotatably coupled to respective ends of the body, wherein the connector isolates the first cable segment from the second cable segment. A method of deployment and retrieval of the seismic cable is also described.
Abstract:
A system for measuring acoustic signature of a target object in water includes a plurality of rigid segments connected to each other to form a longitudinal member and a plurality of floats connected to the longitudinal member. Two buoys are connected at two ends of the longitudinal member and two weights are suspended from the buoys, thus making the longitudinal member neutrally buoyant when suspended in water. A plurality of hydrophones and an acoustic projector of a known source level are connected to the longitudinal member. The system further includes a data acquisition system for receiving signals from hydrophones and a signal processing means for processing signals received by data acquisition and determining acoustic signature of the target object. A depth/pressure sensor may be included. A pinger is located on the target object to measure range of target object to hydrophones. Range to target object is displayed in real time.
Abstract:
A connection system for connecting external devices to a streamer. The connection system comprises three outer collars maintained collinearly aligned by a stabilizing member, such as a lightweight, rigid tube, attached to each outer collar. The tube extends parallel to the bores of the outer collars. The forward and aft outer collars ride on races formed on the periphery of inner collars clamped around mounting structure in the interior of the streamer. An external device is attached to the forward collar and to the intermediate collar, which does not ride on an inner collar. The spacing between the forward and intermediate collars is fixed by the standard spacing of the two attachment points in standard external devices. The spacing between the forward and aft collars is set by the specified spacing of mounting structures in the interior of the streamer.
Abstract:
A marine seismic streamer includes a jacket substantially covering an exterior of the streamer. At least one strength member is disposed along the length of the jacket. A sensor mount is coupled to the strength member. At least one particle motion sensor is suspended within the sensor mount at a selected location along the jacket. The at least one particle motion sensor is suspended in the jacket by at least one biasing device. A mass of the particle motion sensor and a force rate of the biasing device are selected such that a resonant frequency of the particle motion sensor within the sensor jacket is within a predetermined range. The sensor mount is configured such that motion of the jacket, the sensor mount and the strength member is substantially isolated from the particle motion sensor.
Abstract:
A method includes recording a first set of data using a first type of sensor; recording a second set of data using a second type of sensor, the first and second sets of data being contemporaneously acquired by co-located sensors; and removing noise from the first data set using the second data set. An apparatus includes a survey vessel towing an array of towed streamers including a plurality of paired, co-located sensors densely distributed along the streamers. A first one of each sensor pair is of a first type and a second one of each sensor pair is of a second type. A computing apparatus records a first set of data acquire by the first type of sensor and a second data set acquire by the second type of sensor. The computing apparatus then removes noise from the first data set using the second data set.
Abstract:
A method for wrapping continuous strands of steel wire about a seismic cable including interconnected sensor sections and conductor sections where a cross sectional diameter of the sensor section is at least four times that of the conductor section. Two layers of armoring are provided with a first layer wrapped in a first angular direction opposite that of the second layer. A stranding assembly is provided which has two selective positions, one for providing a die hole for stranding the conductor section, another for providing a passage hole for allowing the sensor section to pass after wrapping with armor wire.
Abstract:
The present disclosure generally relates to systems and methods for acquiring seismic data. In one exemplary embodiment, a method for acquiring seismic data is described in which recorder instruments are deployed to the seafloor and utilized for recording pressure wave and shear wave data. An acoustic array, displaced from the seafloor, is also provided for sending acoustic signals to the instruments on the seafloor. The orientation of the instruments on the seafloor is determined via acoustic communication between the acoustic array and the instruments. Related systems and methods for acquiring seismic data are also described.
Abstract:
An optical sensor assembly comprising a plurality of optical fibre sensor coils optically coupled by optical fibre; and an elongate support element, on which said plurality of optical fibre sensor coils and optically coupling optical fibre are mounted is disclosed. The support element has an elastic limit such that when said support element is bent from the elongate axis, the optical fibre fracture limit is reached before the elastic limit is reached. An array of these optical sensor assemblies, the mandrel on which the sensing coils are mounted and their method of manufacture are also disclosed.