摘要:
A disclosed seismic survey system includes one or more streamer(s) each having multiple spaced apart sensor units, and a data recording and control system. Each sensor unit receives a command from the data recording and control system, and operates in an enabled state or a disabled state dependent upon the command. The data recording and control system collects and stores data from enabled sensor units. The sensor units produce data when in the enabled state, and dissipate significantly less electrical power in the disabled state. A described sensor unit includes one or more sensor(s), an analog-to-digital converter, and a control unit that enables or disables the analog-to-digital converter dependent upon the command. A disclosed method for acquiring seismic survey data includes issuing an enable or disable command to each of multiple spaced apart sensor units, and receiving and storing data from those sensor units that are enabled.
摘要:
A method for marine seismic surveying includes towing a streamer in a body of water. The streamer includes a plurality of spaced apart sensor groups, each including a plurality of longitudinally spaced apart pressure sensors and particle motion responsive sensors. Signals are detected at each of the sensors in response to actuation of a seismic energy source. Components of the sampled motion signals in each group above a selected frequency are combined to generate respective group motion signals. Components of the motion responsive signals below the selected frequency are velocity filtered. The velocity filtered signals are combined with the group motion signals to generate full bandwidth motion responsive signals corresponding to each sensor group.
摘要:
A seismic source includes a flextensional shell defining a longer axis and a shorter axis and at least one driver coupled to the flextensional shell proximate an end of the shorter axis. The seismic source may be a component of a marine seismic survey system. The marine seismic survey system may be utilized in a method of marine seismic surveying.
摘要:
A disclosed data acquisition system includes one or more streamers having multiple spaced apart sensor units. At least one sensor unit includes at least one digital sensor employing a quantized feedback loop to produce a digital output signal. A data recording system collects and stores data from the sensor units. The quantized feedback loop may be adapted to exert a quantized force on the sensing element. A described method for acquiring data includes deploying at least one streamer having multiple spaced apart sensor units, where at least a portion of the sensor units include a digital sensor employing a quantized feedback loop to produce a digital output signal. A stimulus event is triggered. Data is received from the sensor units and stored.
摘要:
A method for marine seismic surveying includes towing a streamer in a body of water. The streamer includes a plurality of spaced apart sensor groups, each including a plurality of longitudinally spaced apart pressure sensors and particle motion responsive sensors. Signals are detected at each of the sensors in response to actuation of a seismic energy source. Components of the sampled motion signals in each group above a selected frequency are combined to generate respective group motion signals. Components of the motion responsive signals below the selected frequency are velocity filtered. The velocity filtered signals are combined with the group motion signals to generate full bandwidth motion responsive signals corresponding to each sensor group.
摘要:
A detector for a marine electromagnetic survey system includes a housing arranged to minimize turbulence when the housing is towed through a body of water, and to minimize motion of the housing in any direction other than the tow direction. The housing includes at least one of an electric field and a magnetic field sensing element associated therewith.
摘要:
A method for generating seismic energy for subsurface surveying includes operating a first seismic vibrator and operating at least a second seismic vibrator in a body of water substantially contemporaneously with the operating the first seismic vibrator. Each vibrator has a different selected frequency response, and the vibrators each are operated at a depth in the water such that a surface ghost amplifies a downward output of each vibrator within a selected frequency range. A signal used to drive each vibrator has a frequency range corresponding to the frequency range of each vibrator.
摘要:
A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of the jacket. The strength member is disposed inside the jacket. At least one seismic sensor is disposed in an interior of the jacket. An acoustically transparent material fills void space in the interior of the jacket. At least one longitudinally compressible element is disposed at a selected position along the streamer. The longitudinally compressible element fills substantially all void space within a cross-section of the interior of the jacket to separate the material into two compartments, thus attenuating transmission of acoustic waves in the material across the element.
摘要:
An electromagnetic sensor cable includes at least one strength member configured to be coupled to a vessel for towing in a body of water and extending along the length of the cable. A jacket covers the strength member and extends along the length of the cable. At least one electrode mounting sleeve is disposed along the jacket and is coupled at its longitudinal ends to one end of a segment of the jacket. The longitudinal ends of the sleeve are configured to mate with a corresponding end of the jacket segment. The sleeve includes a passage therethrough for the at least one strength member. The sleeve includes a mounting surface for a fiber electrode material thereon disposed between the longitudinal ends of the sleeve. At least one electrical contact surface is disposed on the mounting surface. Electrically conductive fiber electrode material is disposed on the mounting surface and is in electrical contact with the electrical contact surface.
摘要:
A seismic streamer includes a jacket covering an exterior of the streamer. At least one strength member extends along the length of the jacket. The strength member is disposed inside the jacket. At least one seismic sensor is disposed in an interior of the jacket. A plurality of spacers is disposed at spaced apart positions along the strength member. An acoustically transparent material fills void space in the interior of the jacket. At least one structural parameter is selected to minimize pressure variations in the material resulting from axial elongation of the streamer under tension.