Patent classifications
G01V1/36
METHOD AND SYSTEM FOR SEISMIC DENOISING USING OMNIFOCAL REFORMATION
Methods and systems for determining an image of a subterranean region of interest are disclosed. The method includes obtaining a seismic dataset and a geological dip model for the subterranean region of interest and determining a set of input seismic gathers from the seismic dataset. The method further includes determining a central seismic gather and a set of neighboring seismic gathers in a vicinity of the central seismic gather from the set of seismic gathers, determining a set of dip-corrected neighboring seismic gathers based, at least in part, on the set of neighboring seismic gathers and a geological dip from the geological dip model, and determining a noise-attenuated central seismic gather by combining the dip-corrected neighboring seismic gathers and the central seismic gather. The method still further includes forming the image of the subterranean region of interest based, at least in part, on the noise-attenuated central seismic gather.
Noise attenuation
Noise can be attenuated in marine seismic data from a marine seismic survey. A first near-continuous measurement of a wavefield and a second near-continuous measurement of the wavefield recorded from a marine seismic survey can be equalized, a coherent portion of the equalized second near-continuous measurement can be collapsed, and a noise model can be derived. The noise model can be subtracted from the second near-continuous measurement.
METHOD AND APPARATUS FOR EXTRACTING DOWNGOING WAVELET AND ATTENUATION PARAMETERS BY USING VERTICAL SEISMIC DATA
A method for extracting a downgoing wavelet and attenuation parameters from VSP data, comprising: performing upgoing and downgoing P-waves separation processing on VSP data to obtain downgoing P-wave data; performing a FFT on seismic data with a preset time window length starting from the P-wave first arrival time and cut from the downgoing P-wave data to obtain FFT transformed downgoing P-wave data and a multi-trace downgoing P-wave log spectrum; subtracting a downgoing wavelet log spectrum from the multi-trace downgoing P-wave log spectrum to obtain a wavelet-corrected multi-trace downgoing P-wave log spectrum; performing, based on parameters of the wavelet-corrected multi-trace downgoing P-wave log spectrum, a correction and an inverse FFT on the FFT transformed downgoing P-wave data to obtain a downgoing wavelet; and obtaining attenuation parameters based on P-wave first arrival time and the parameters of the wavelet-corrected multi-trace downgoing P-wave log spectrum. The method can extract a downgoing wavelet and attenuation parameters with high accuracy. Also provided are an apparatus for extracting a downgoing wavelet and attenuation parameters from VSP data, a computer device, and a computer-readable storage medium.
Real-time processing and control of DAS VSP surveys
A system for processing DAS VSP surveys in real-time is provided. The system includes a DAS data collection system coupled to at least one optical fiber at least partially positioned within a wellbore and configured to repeatedly activate a seismic source of energy. The system further includes an information processing system connected to the DAS data collection system. A seismic dataset is received from the DAS data collection system. The seismic dataset includes a plurality of seismic data records. Two or more of the plurality of seismic data records are combined into a stack. A quality metric indicative of a desired signal-to-noise ratio or incoherence of the stack is determined for each processed seismic dataset collected from a repeated source. Instructions are sent to the DAS data collection system to stop activating the seismic source, in response to determining that the quality metric has reached a predefined threshold.
Correlation Techniques for Passive Electroseismic and Seismoelectric Surveying
A method for surveying, may include receiving, by a processor, first survey data from a first source, the first source comprising a first signal generated by a subsurface earth formation in response to a passive-source electromagnetic signal, wherein the electromagnetic signal is generated by an electroseismic or seismoelectric conversion of the passive-source electromagnetic signal. The method may also include receiving, by the processor, second survey data from a second source and processing the first survey data and the second survey data to determine one or more properties of a subsurface earth formation.
Correlation Techniques for Passive Electroseismic and Seismoelectric Surveying
A method for surveying, may include receiving, by a processor, first survey data from a first source, the first source comprising a first signal generated by a subsurface earth formation in response to a passive-source electromagnetic signal, wherein the electromagnetic signal is generated by an electroseismic or seismoelectric conversion of the passive-source electromagnetic signal. The method may also include receiving, by the processor, second survey data from a second source and processing the first survey data and the second survey data to determine one or more properties of a subsurface earth formation.
Separation of blended marine seismic survey data acquired with simultaneous multi-source actuation
Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Recorded data may be aligned to a primary source. A deblending procedure may be iteratively applied to produce a residual term and deblended estimates for the primary source and one or more secondary sources. Following an iteration of the deblending procedure, the resultant data may be sorted according to a domain that renders the one or more secondary sources incoherent with respect to the primary source. The domain used for sorting may be different from a domain used to sort during an immediately prior iteration. In embodiments, the deblending procedure may use coherency filtering, and the coherency filtering may be weighted according to a signal-to-noise metric generated from the data being deblended.
Separation of blended marine seismic survey data acquired with simultaneous multi-source actuation
Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Recorded data may be aligned to a primary source. A deblending procedure may be iteratively applied to produce a residual term and deblended estimates for the primary source and one or more secondary sources. Following an iteration of the deblending procedure, the resultant data may be sorted according to a domain that renders the one or more secondary sources incoherent with respect to the primary source. The domain used for sorting may be different from a domain used to sort during an immediately prior iteration. In embodiments, the deblending procedure may use coherency filtering, and the coherency filtering may be weighted according to a signal-to-noise metric generated from the data being deblended.
SYSTEMS AND METHODS FOR PERFORMING SEISMIC SURVEY IN SHALLOW WATER AREAS
A method may include receiving, via a processor, multiple seismic datasets acquired simultaneously in response to multiple seismic waves generated by multiple sources towed by one or more vessels. The multiple seismic datasets may include an ocean bottom node datasets, a towed streamer dataset, a near field hydrophones dataset, and a vertical seismic profile dataset. The method may sensors also include performing coordinated seismic data processing using the multiple seismic datasets to generate seismic data representative of one or more subsurface regions below the water bottom, building a velocity model based on the seismic data, and generating seismic images representative of the water bottom and the one or more subsurface regions based on the velocity model.
SYSTEMS AND METHODS FOR PERFORMING SEISMIC SURVEY IN SHALLOW WATER AREAS
A method may include receiving, via a processor, multiple seismic datasets acquired simultaneously in response to multiple seismic waves generated by multiple sources towed by one or more vessels. The multiple seismic datasets may include an ocean bottom node datasets, a towed streamer dataset, a near field hydrophones dataset, and a vertical seismic profile dataset. The method may sensors also include performing coordinated seismic data processing using the multiple seismic datasets to generate seismic data representative of one or more subsurface regions below the water bottom, building a velocity model based on the seismic data, and generating seismic images representative of the water bottom and the one or more subsurface regions based on the velocity model.