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US 12,761,382 B2Granted
Passive low frequency seismic (LFS) system and method to detect and image subsurface search objects and fluid properties
AssigneeTenzor Geo LTD
InventorsVasiliy Ryzhov, Sergey Feofilov, Ilshat Sharapov, Dmitry Ryzhov, Roy Bitrus, Ildar Gadeev
Life of this patent
Estimating the term…
Abstract
Systems and methods for applying passive low frequency seismic (LFS) techniques to estimate the presence of a search object, its properties, and properties of the exterior environment for onshore or offshore surveys. The process includes the acquisition of LFS data, multi-phase data simulation and data processing using advanced processing graphs that includes seismic interferometry approaches and adapted inversion techniques.
Claims20
A method for detecting and imaging a subsurface search object, the method comprising:
- positioning a plurality of sensors in a predetermined area and simultaneously recording ambient microseismic signals with the plurality of sensors, the ambient microseismic signals comprising at least a vertical component and a horizontal component;
- processing the ambient microseismic signals including by:
- filtering correlated noise from the vertical component using at least one horizontal component of at least one of the sensors;
- filtering at least one quasi-harmonic interference component while preserving a broadband background component of the recorded ambient microseismic signals;
- excluding record sections contaminated by broadband interference;
- for a plurality of pairs of simultaneously recording sensors, computing pairwise cross-correlations from the recorded ambient microseismic signals and forming a cross-correlation tensor from the pairwise cross-correlations;
- using the cross-correlation tensor derived from the pairwise cross-correlations to suppress a scattered surface-wave component and extract a response corresponding to vertically propagating compressional waves from the recorded ambient microseismic signals;
- and
- filtering gathered pairwise cross-correlation data to exclude inclined-wave components-correlation functions;
- generating a modeled response corresponding to vertically propagating compressional waves in the predetermined area by seismic simulation in a multiphase medium, wherein the seismic simulation is based on prior data for the predetermined area;
- and
- estimating at least one property of the subsurface search object by comparing the extracted response corresponding to vertically propagating compressional waves with the modeled response corresponding to vertically propagating compressional waves.
9 more elements
A system for detecting and imaging a subsurface search object, the system comprising:
- a plurality of sensors configured to simultaneously record ambient microseismic signals in a predetermined area, the ambient microseismic signals including at least a vertical component and a horizontal component;
- a processing module configured to process the ambient microseismic signals including by:
- filtering correlated noise from the vertical component using at least one horizontal component of at least one of the sensors;
- filtering at least one quasi-harmonic interference component while preserving a broadband background component of the recorded ambient microseismic signals;
- excluding record sections contaminated by broadband interference;
- computing pairwise cross-correlations for a plurality of pairs of simultaneously recording sensors and forming a cross-correlation tensor derived from the pairwise cross-correlations;
- using the tensor derived from the pairwise cross-correlations to suppress a scattered surface-wave component and extract a response corresponding to vertically propagating compressional waves from the recorded ambient microseismic signals;
- and
- filtering gathered pairwise cross-correlation data to exclude inclined-wave components;
- a simulation module configured to:
- generate a modeled response corresponding to vertically propagating compressional waves in the predetermined area by seismic simulation in a multiphase medium, wherein the seismic simulation is based on prior data for the predetermined area;
- and
- estimate at least one property of the subsurface search object by comparing the extracted response corresponding to vertically propagating compressional waves with the modeled response corresponding to vertically propagating compressional waves.
10 more elements
A method for detecting and imaging a subsurface search object, the method comprising:
- processing simultaneously recorded ambient microseismic signals comprising at least a vertical component and a horizontal component collected in a predetermined area including by:
- filtering correlated noise from the vertical component using at least one horizontal component;
- filtering at least one quasi-harmonic interference component while preserving a broadband background component of the recorded ambient microseismic signals;
- excluding record sections contaminated by broadband interference;
- for a plurality of pairs of simultaneously recording sensors, computing pairwise cross-correlations from the recorded ambient microseismic signals and forming a cross-correlation tensor from the pairwise cross-correlations;
- using the tensor derived from the pairwise cross-correlations to suppress a scattered surface-wave component and extract a response corresponding to vertically propagating compressional waves from the recorded ambient microseismic signals;
- and
- filtering gathered pairwise cross-correlation data to exclude inclined-wave
- generating a modeled response corresponding to vertically propagating compressional waves in the predetermined area by seismic simulation in a multiphase medium, wherein the seismic simulation is based on prior data for the predetermined area;
- and
- estimating at least one property of the subsurface search object by comparing the extracted response corresponding to vertically propagating compressional waves with the modeled response corresponding to vertically propagating compressional waves.
8 more elements
Dependencies are inferred from the claim text.