Seismic acquisition and filtering
AssigneeSchlumberger Technology Corporation
InventorsYing Ji, Julian Edward Kragh, Ali Ozbek
Life of this patent
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Abstract
Designing a multi-dimensional Finite Impulse Response FIR digital filter to attenuate the coherent noise while preserving reflection signals on seismic data, particular in land seismics, includes computing filter coefficients to minimize an l-norm function of differences between a response of a filter with the computed coefficients and a predetermined response which attenuates signals outside a predetermined range of slowness relative to signals within the predetermined range of slowness. Additional constraints may be imposed on the coefficients to improve the attenuation of signals outside the predetermined range of slowness of the desired reflection signals, and/or to improve uniformity within the desired range.
Claims17
A method of seismic surveying comprising:
- propagating an acoustic or electromagnetic field through at least one subsurface layer of the earth;
- acquiring seismic data at a plurality of individual sensors for the field, placed at discrete locations spaced apart from one another;
- storing the received seismic data in digital form on a non-transitory computer-readable storage medium;
- and
- operating a computer to process the stored digital seismic data by applying a filter to signals from individual sensors,
- wherein the filter contains filter coefficients and the computational processing comprises computing filter coefficients to minimise an l-norm function of differences between a response of the filter with the computed coefficients and a predetermined response which attenuates signals outside a predetermined range of slowness relative to signals within the predetermined range of slowness.
The method of seismic surveying comprising:
- propagating an acoustic or electromagnetic field through at least one subsurface layer of the earth;
- acquiring digital seismic signals representing seismic energy received as a function of time at a plurality of individual sensors for the field, placed at discrete locations spaced apart from one another with irregular spacing;
- storing the received digital seismic signals on a non-transitory computer-readable storage medium;
- and
- operating a computer to process the stored digital seismic signals by applying a filter to signals from individual sensors,
- wherein the filter contains filter coefficients and the computational processing comprises computing filter coefficients to minimize, over a range of frequencies,
- an l-norm function of differences between a response of the filter with the computed coefficients and a predetermined response which attenuates signals outside a predetermined range of slowness relative to signals within the predetermined range of slowness.
Dependencies are inferred from the claim text.