Abstract:
According to one or more aspects of the invention, a marine seismic survey method comprises towing at least two streamers below a sea surface forming a survey spread, each streamer comprising a survey sensor and a profiler; and at each profiler, emitting an acoustic signal; recording an echo of the emitted signal at the profiler; and determining a parameter from the recorded echo, the parameter comprising at least one selected from the group of a distance between the profiler and the sea surface, a water current vector and a sea surface slope.
Abstract:
Measurement data is received from first and second seismic sensors, where the first and second seismic sensors are oriented in opposite directions. Each of the first and second seismic sensors has a sensing element responsive to pressure and particle motion. The signals can be combined to remove the particle motion component of the measurement data and obtain pressure-only data. Alternatively, the signals can be combined to deghost the received measurement data.
Abstract:
A computer-implemented method includes accessing a set of multicomponent marine noise data exhibiting a plurality of polarization vectors at each of a plurality of co-located pressure and particle motion data points on a marine seismic survey apparatus; and determining a set of perturbation noise data for the marine seismic survey apparatus from the polarization vectors. Computer readable program storage media are encoded with instructions that, when executed by a processor, perfume the computer-implemented method. One computing apparatus is programmed to perform the computer-implemented method.
Abstract:
A seismic cable (110) and a method for producing a seismic cable are disclosed. The seismic cable (110) comprises a sensor module (130); at least one lead (210) to or from the sensor module (130); a stress member (225) extending continuously through the sensor module (130); and a sheath (230) enclosing the leads (210) and the stress member (225), the sheath (230) terminating at each end of the sensor module (130), and at least one mechanical guide (240) in the sensor module (130) deflecting the stress member (230). The method comprises providing a cable core including a stress member (225) and a lead (210); enclosing the cable core in a sheath (230); providing an opening in the sheath (230); and assembling a sensor module (130) to the cable core over the opening such that the stress member (225) extends continuously through the sensor module (130).
Abstract:
An apparatus includes particle motion sensors and a streamer that contains the particle motion sensors. The streamer is to be towed in connection with a seismic survey, and the towing of the streamer produces a turbulent flow. The streamer includes an inner cable that contains the particle motion sensors and a fluid containing layer to surround the inner cable to reduce noise otherwise sensed by the particle motion sensors due to the turbulent flow.
Abstract:
A technique includes designing a streamer, which includes a cable and seismic sensors based at least in part on a relationship between vibration noise and a bending stiffness of the cable.
Abstract:
A housing for a seismic sensing element (3) for use on the earth's surface comprises connecting means (5) for connecting the housing (3) to a support cable (2) so as to allow relative movement between the sensor housing (3) and the cable (2). This de-couples the sensor housing from the support cable, and improves the fidelity of the sensor.The connecting means (5) preferably comprises resilient connecting elements, to prevent the transmission of vibrations between the support cable and the sensor housing.The sensor housing (3) preferably has a flat base (1), so that there is good coupling between the sensor housing and the earth. Alternatively, the sensor housing can be fitted with a base member ((24a, 24b, 24c) that has at least one flat face (26, 26a, 26b, 26c).
Abstract:
Methods and apparatus for acquiring seismic data using a seabed seismic data cable positioned on a seabed are described, one method including deploying a seabed seismic cable, the cable comprising two or more active sections separated by at least one jumper section; and acquiring seabed seismic data using the seabed seismic cable. Certain methods include analyzing spacing needed between active sensor units in the active sections prior to deploying the seabed seismic cable, and selecting a length of the jumper section based on the analysis. 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 or meaning of the claims. 37 CFR 1.72(b).
Abstract:
Apparatus and methods for acquiring seismic data using a seabed seismic data cable positioned on a seabed are described, including controlling effect of water flow on the cable during data acquisition using fairing elements, which may be caused to extend from the cable generally transversely as water flows past the cable. Alternate paths for water underneath the cable may also be provided, reducing lift forces on the cable. 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 or meaning of the claims. 37 CFR 1.72(b).
Abstract:
A housing for a seismic sensing element (3) for use on the earth's surface comprises connecting means (5) for connecting the housing (3) to a support cable (2) so as to allow relative movement between the sensor housing (3) and the cable (2). This de-couples the sensor housing from the support cable, and improves the fidelity of the sensor. The connecting means (5) preferably comprises resilient connecting elements, to prevent the transmission of vibrations between the support cable and the sensor housing. The sensor housing (3) preferably has a flat base (1), so that there is good coupling between the sensor housing and the earth. Alternatively, the sensor housing can be fitted with a base member ((24a, 24b, 24c) that has at least one flat face (26, 26a, 26b, 26c).