摘要:
A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands.
摘要:
A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands.
摘要:
Methods and apparatus for borehole seismic survey are disclosed comprising a first seismic source under water at a first location and a second seismic source at a second, deeper location. Seismic signals from the seismic sources are recorded with synchronized sensors located in a borehole and source signature data are obtained by combining the recorded seismic signals such that low and high frequency content of the combined source signature data is extended relative to the source signature of the first seismic source and the second seismic source.
摘要:
The present invention provides a method and apparatus for determining the position of a seismic cable being used to perform a marine seismic survey. The apparatus includes at least one seismic sensor and a plurality of sources deployed in a manner that is structurally independent of the seismic sensors and adapted to provide a positioning signal distinguishable from a seismic survey signal to the seismic sensors.
摘要:
A marine cable for seismic surveys is described with a plurality of ceramic pressure sensors arranged in groups of at least two pressure sensors with a group output being representative of the vertical pressure gradient at the group location, and an inclinometric system including one or more transducers for determining the orientation of the sensors of the group in order to determine their true vertical separation.
摘要:
An improved de-ghosting method and system that utilizes multi-component marine seismic data recorded in a fluid medium. The method makes use of two types of data: pressure data that represents the pressure in the fluid medium, such as sea water, at a number of locations; and vertical particle motion data that represents the vertical particle motion of the acoustic energy propagating in the fluid medium at a number of locations within the same spatial area as the pressure data. The vertical particle motion data can be in various forms, for example, velocity, pressure gradient, displacement, or acceleration. A spatial filter is designed so as to be effective at separating up and down propagating acoustic energy over substantially the entire range of non-horizontal incidence angles in the fluid medium. The spatial filter is applied to either the vertical particle motion data or to the pressure data, and then combined with the other data to generate pressure data that has its up and down propagating components separated.
摘要:
A marine cable for seismic surveys is described with a plurality of ceramic pressure sensors (901-904) arranged in groups of at least two pressure sensors with a group output being representative of the vertical pressure gradient at the group location, and an inclinometric system including one or more transducers for determining the orientation of the sensors of the group in order to determine their true vertical separation.
摘要:
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).
摘要:
A sonde and an apparatus for the deployment thereof against a well casing is described, the sonde comprising a resilient C-shaped member and at least one sensor.
摘要:
An improved de-ghosting method and system that utilizes multi-component marine seismic data recorded in a fluid medium. The method makes use of two types of data: pressure data that represents the pressure in the fluid medium, such as sea water, at a number of locations; and vertical particle motion data that represents the vertical particle motion of the acoustic energy propagating in the fluid medium at a number of locations within the same spatial area as the pressure data. The vertical particle motion data can be in various forms, for example, velocity, pressure gradient, displacement, or acceleration. A spatial filter is designed so as to be effective at separating up and down propagating acoustic energy over substantially the entire range of non-horizontal incidence angles in the fluid medium. The spatial filter is applied to either the vertical particle motion data or to the pressure data, and then combined with the other data to generate pressure data that has its up and down propagating components separated.