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).
Abstract:
A technique facilitates collection and use of data on subterranean formations. The technique comprises obtaining gravity measurements through the use of seismic streamers. At least one streamer is provided such that each streamer has multiple sensors, e.g. accelerometers. The at least one streamer is towed with a tow vessel, and gravity data are accumulated via the multiple sensors during towing.
Abstract:
A technique includes obtaining first measurements acquired by sensors of a towed seismic streamer, which are indicative of an inclination of the streamer. Based at least in part on the measurements, a shape of the streamer while in tow is determined.
Abstract:
Measurement data acquired by at least one sensor in a cable structure towed through a body of water is received. A torsional vibration noise component in the measurement data is estimated. The torsional vibration noise component is used to estimate a rotation angle of the at least one survey sensor with respect to a reference coordinate system of the cable structure.
Abstract:
A seismic sensor module includes sensing elements arranged in a plurality of axes to detect seismic signals in a plurality of respective directions, and a processor to receive data from the sensing elements and to determine inclinations of the axes with respect to a particular orientation. The determined inclinations are used to combine the data received from the sensing elements to derive tilt-corrected seismic data for the particular orientation.