摘要:
A method of acquiring or processing multi-component seismic data obtained from seismic signals propagating in a medium, the method comprising the steps of: selecting a first portion of the seismic data in which the first arrival contains only upwardly propagating seismic energy above the seafloor; and determining a first calibration filter from the first portion of the seismic data, the first calibration filter being to calibrate a first component of the seismic data relative to a second component of the seismic data.
摘要:
A method determining a calibration filter to calibrate a first component of multi-component seismic data relative to a second component of the seismic data comprises determining the calibration filter from a portion of the seismic data that contains only events arising from critical refraction of seismic energy. The method is particularly suitable for long-off-set data, since the first arrival will be a critical refraction event and an automatic picking method may be used. The present invention also provides a wavenumber dependent calibration filter that is obtained from a calibration filter obtained from data in one offset range and another calibration filter obtained from data in another offset range.
摘要:
A method and apparatus implementing a technique for mitigating noise in seismic data are presented. The technique includes estimating a noise component in a set of multicomponent seismic data representing a recorded wavefield from the relationship at the free surface of an upgoing component and a downgoing component decomposed from the recorded wavefield; and removing the estimated noise component from the seismic data. The noise component can be estimated by decomposing a recorded wavefield into an upgoing component and a downgoing component and isolating a noise component in the recorded wavefield from the relationship of the decomposed upgoing and downgoing components at the free surface.
摘要:
Implementations of various technologies for processing seismic data. In one implementation, the seismic data may be processed by creating a fictitious source-receiver line connecting a source with a receiver location of interest, projecting one or more receiver locations adjacent the receiver location of interest onto the fictitious source-receiver line and decomposing seismic data on the receiver locations disposed on the fictitious source-receiver line into up-going wavefields and down-going wavefields.
摘要:
A method of processing seismic data that includes including first and second modes of seismic energy where the second mode has been generated by partial mode conversion of the first mode at a boundary face of a layer of the seabed includes the step of cross-correlating a trace acquired at a receiver and including events corresponding to the first mode with a trace acquired at the same receiver and including events corresponding to the second mode. An event in the cross-correlated data that corresponds to partial mode conversion is identified, and the amplitude of this event is normalized, for example relative to the amplitude of the peak in the cross-correlogram at zero time delay. Information about the effects of the static shift produced by the layer and/or about vector infidelity can be arrived from normalized cross-correlograms for receivers in a receiver array.
摘要:
A technique includes obtaining multi-component seismic data acquired by two or more seismic sensors while in tow. The multi-component seismic data is indicative of a pressure wavefield and particle motion. The technique includes based on the data, determining at least one high order (i.e., second order or higher) spatial derivative of the pressure wavefield.
摘要:
The present invention relates to a method of processing data representing energy propagating through a medium (e.g., acoustic, elastic or electromagnetic energy) and describes an efficient and flexible e approach to forward modeling and inversion of such energy for a given medium. The representation theorem for the wave-equation is used, in combination with time-reversal invariance and reciprocity, to express the Green's function between two points in the interior of the model as an integral over the response in those points due to sources regularly distributed on a surface surrounding the medium and the points.
摘要:
A method of processing seismic data that includes including first and second modes of seismic energy where the second mode has been generated by partial mode conversion of the first mode at a boundary face of a layer of the seabed includes the step of cross-correlating a trace acquired at a receiver and including events corresponding to the first mode with a trace acquired at the same receiver and including events corresponding to the second mode. An event in the cross-correlated data that corresponds to partial mode conversion is identified, and the amplitude of this event is normalized, for example relative to the amplitude of the peak in the cross-correlogram at zero time delay. Information about the effects of the static shift produced by the layer and/or about vector infidelity can be arrived from normalized cross-correlograms for receivers in a receiver array.
摘要:
A method and apparatus implementing a technique for mitigating noise in seismic data are presented. The technique includes estimating a noise component in a set of multicomponent seismic data representing a recorded wavefield from the relationship at the free surface of an upgoing component and a downgoing component decomposed from the recorded wavefield; and removing the estimated noise component from the seismic data. The noise component can be estimated by decomposing a recorded wavefield into an upgoing component and a downgoing component and isolating a noise component in the recorded wavefield from the relationship of the decomposed upgoing and downgoing components at the free surface.
摘要:
A method of processing seismic data that includes including first and second modes of seismic energy where the second mode has been generated by partial mode conversion of the first mode at a boundary face of a layer of the seabed includes the step of cross-correlating a trace acquired at a receiver and including events corresponding to the first mode with a trace acquired at the same receiver and including events corresponding to the second mode. An event in the cross-correlated data that corresponds to partial mode conversion is identified, and the amplitude of this event is normalized, for example relative to the amplitude of the peak in the cross-correlogram at zero time delay. Information about the effects of the static shift produced by the layer and/or about vector infidelity can be arrived from normalized cross-correlograms for receivers in a receiver array.