Attenuation of low-frequency noise in continuously recorded wavefields
AssigneePGS Geophyscial AS
InventorsStian Hegna, Tilman Klüver
Life of this patent
Estimating the term…
Abstract
Processes and systems for imaging a subterranean formation using continuously recorded seismic data obtained during a marine seismic geophysical survey of the subterranean formation are described herein. The processes and systems compute upgoing pressure data at stationary-receiver locations, and low-frequency noise attenuation processes and systems are applied to the upgoing pressure wavefield data to obtain low-frequency noise attenuated upgoing pressure wavefield data. An image of the subterranean formation, or data indicative thereof, may be generated using the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations.
Claims21
In a process for generating an image of a subterranean formation based on pressure data that were continuously recorded during a geophysical survey, the improvement comprising:
- computing upgoing pressure wavefield data at stationary-receiver locations based on continuously recorded pressure data and vertical velocity data;
- computing a total source wavefield based on source wavefields emitted from individual airguns of a source;
- attenuating low-frequency noise in the upgoing pressure wavefield based on the total source wavefield to obtain low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- and
- generating an image of the subterranean formation, or data indicative thereof, based at least in part on the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations, thereby reducing low-frequency noise artifacts in the image.
A computer system for computing an image of a subterranean formation, the system comprising:
- one or more processors;
- one or more data-storage devices;
- and
- machine-readable instructions stored in the one or more data-storage devices that when executed using the one or more processors controls the system to perform operations comprising:
- computing upgoing pressure wavefield data at stationary-receiver locations based on continuously recorded pressure and vertical velocity data obtained during a marine geophysical survey of the subterranean formation;
- computing a total source wavefield based on recorded source wavefields emitted from individual airguns that were repeatedly activated during the survey;
- attenuating low-frequency noise in the upgoing pressure wavefield based on the total source wavefield to obtain low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- and
- generating an image of the subterranean formation, or data indicative thereof, based at least in part on the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations.
A non-transitory computer-readable medium encoded with machine-readable instructions that, when executed by one or more processors of a computer system, perform operations comprising:
- computing upgoing pressure wavefield data at stationary-receiver locations based on continuously recorded pressure data and vertical velocity data obtained during a marine geophysical survey of the subterranean formation;
- computing a total source wavefield based on source wavefields emitted from individual airguns that were repeatedly activated during the survey;
- attenuating low-frequency noise in the upgoing pressure wavefield based on the total source wavefield to obtain low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- and
- generating an image of the subterranean formation, or data indicative thereof, based at least in part on the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations.
Apparatus for generating an image of a subterranean formation based on continuously recorded pressure data and vertical velocity data obtained during a marine geophysical survey of the subterranean formation, the apparatus comprising:
- means for computing upgoing pressure wavefield data at stationary-receiver locations based on continuously recorded pressure data and vertical velocity data;
- means for computing a total source wavefield based on source wavefields emitted from airguns that were repeatedly activated during the survey:
- means for attenuating low-frequency noise in the upgoing pressure wavefield based on the total source wavefield to obtain low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- and
- means for generating an image of the subterranean formation, or data indicative thereof, based at least in part on the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations.
A method for manufacturing a geophysical data product, the method comprising:
- computing upgoing pressure wavefield data at stationary-receiver locations based on continuously recorded pressure data and vertical velocity data obtained during a marine geophysical survey of a subterranean formation;
- computing a total source wavefield based on source wavefields emitted from individual airguns that were repeatedly activated during the survey;
- attenuating low-frequency noise in the upgoing pressure wavefield based on the total source wavefield to obtain low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- generating an image of the subterranean formation, or data indicative there, based at least in part on the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations;
- and
- storing the image in a non-transitory computer-readable medium.
Dependencies are inferred from the claim text.