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公开(公告)号:US11428834B2
公开(公告)日:2022-08-30
申请号:US16221128
申请日:2018-12-14
Applicant: PGS Geophysical AS
Abstract: This disclosure describes processes and systems for generating a high-resolution velocity model of a subterranean formation from recorded seismic data gathers obtained in a marine seismic survey of the subterranean formation. A velocity model is computed by iterative FWI using reflections, resolving the velocity field of deep subterranean targets without requiring ultralong offsets. The processes and systems use of an impedance sensitivity kernel to characterize reflections in a modeled wavefield, and then use the reflections to compute a velocity sensitivity kernel that is used to produce low-wavenumber updates to the velocity model. The iterative process is applied in a cascade such that position of reflectors and background velocity are simultaneously updated. Once the low-wavenumber components of the velocity model are updated, the velocity model is used as an input of conventional FWI to introduce missing velocity components (i.e., high-wavenumber) to increase the resolution of the velocity model.
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公开(公告)号:US20150362611A1
公开(公告)日:2015-12-17
申请号:US14550001
申请日:2014-11-21
Applicant: PGS Geophysical AS
Inventor: Didier B. P. Lecerf , Nizar Chemingui , Alejandro A. Valenciano Mavilio , Shaoping Lu
IPC: G01V1/34
CPC classification number: G01V1/28 , G01V2210/1293 , G01V2210/1423 , G01V2210/56 , G01V2210/57
Abstract: Techniques are disclosed relating to geophysical analysis. In one embodiment, a method includes receiving seismic data for a geophysical formation recorded during a seismic survey using one or more seabed sensors and one or more sources. In this embodiment, the method includes determining a seismic gather for a location in the geophysical formation, modifying the seismic gather by interchanging source-receiver definitions for the seismic gather, and imaging the location using the modified gather. In this embodiment, the imaging uses higher-order reflections recorded in the seismic gather. In some embodiments, the method includes separating up-going and down-going wavefields and separately imaging using the up-going wavefield and the down-going wavefield.
Abstract translation: 公开了与地球物理分析有关的技术。 在一个实施例中,一种方法包括使用一个或多个海底传感器和一个或多个源接收在地震勘测期间记录的地球物理地层的地震数据。 在该实施例中,该方法包括确定用于地球物理地层中的位置的地震采集,通过交换地震采集的源 - 接收机定义来修改地震采集,以及使用修改的集合对位置进行成像。 在该实施例中,成像使用记录在地震采集中的高阶反射。 在一些实施例中,该方法包括使用上行波场和下行波场分离上行和下行波场并分开成像。
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公开(公告)号:US11092708B2
公开(公告)日:2021-08-17
申请号:US16350083
申请日:2018-09-21
Applicant: PGS Geophysical AS
Inventor: Shaoping Lu , Faqi Liu , Alejandro A. Valenciano Mavilio , Nizar Chemingui
Abstract: This disclosure describes processes and systems for generating a seismic image of a subterranean formation from recorded seismic data gathers obtained in a marine seismic survey of the subterranean formation. The seismic data comprises recorded pressure and vertical velocity wavefields that are used to separate the recorded pressure wavefield into upgoing and downgoing pressure wavefields. A seismic image is computed from the subterranean formation based on a product of the downgoing pressure wavefield and a migration operator applied to the upgoing pressure wavefield. The downgoing pressure wavefield is a boundary source wavefield and the upgoing pressure wavefield is boundary receiver wavefield of the migration operator. The seismic image is iteratively updated by computing a residual seismic image based on the upgoing pressure wavefield and adding the residual seismic image to the seismic image. The final seismic image displays increased illumination and reduced crosstalk artifacts compared to conventional seismic imaging techniques.
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公开(公告)号:US20190257968A1
公开(公告)日:2019-08-22
申请号:US15939711
申请日:2018-03-29
Applicant: PGS Geophysical AS
Inventor: Lingyun Qiu , Jaime Ramos-Martinez , Alejandro A. Valenciano Mavilio
Abstract: Inversion with exponentially encoded seismic data can include exponentially encoding acquired seismic data and associated synthetic seismic data, storing the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data, determining a one-dimensional (1D) Wasserstein distance between the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data, and generating an adjoint source based on the 1D Wasserstein distance. The example method also includes adapting a dynamic weight implementation of a sensitivity kernel to the adjoint source to build a gradient associated with the acquired seismic data and the associated synthetic seismic data, and iteratively inverting a waveform associated with the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data based on the gradient. An image of a subsurface location can be generated based on results of the iterative inversions.
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5.
公开(公告)号:US09829592B2
公开(公告)日:2017-11-28
申请号:US14850540
申请日:2015-09-10
Applicant: PGS Geophysical AS
Inventor: Jaime Ramos-Martinez , Alejandro A. Valenciano Mavilio
CPC classification number: G01V1/368 , G01V1/282 , G01V1/3808 , G01V2210/679 , G01V2210/74
Abstract: In one embodiment, a reverse time migration module is configured with a visco-acoustic wave equation for media with heterogeneous attenuation solved using a pseudo-analytical method. Seismic data is obtained for a zone of interest, and a model is created for the zone of interest. The model has spatial variability in velocity and quality factor. Pseudo-analytic Q-compensating reverse time migration (PA-Q-RTM) is performed using the reverse time migration module and the model for the zone of interest to obtain PA-Q-RTM seismic data. In another embodiment, a system for processing seismic data includes a reverse time migration module configured with a visco-acoustic wave equation that is solved from the pseudo-analytical method. The system operates to obtain seismic data for a zone of interest and perform PA-Q-RTM using a model for the zone of interest to obtain PA-Q-RTM seismic data for the zone of interest. Other embodiments and features are also disclosed.
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公开(公告)号:US11215726B2
公开(公告)日:2022-01-04
申请号:US15939711
申请日:2018-03-29
Applicant: PGS Geophysical AS
Inventor: Lingyun Qiu , Jaime Ramos-Martinez , Alejandro A. Valenciano Mavilio
Abstract: Inversion with exponentially encoded seismic data can include exponentially encoding acquired seismic data and associated synthetic seismic data, storing the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data, determining a one-dimensional (1D) Wasserstein distance between the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data, and generating an adjoint source based on the 1D Wasserstein distance. The example method also includes adapting a dynamic weight implementation of a sensitivity kernel to the adjoint source to build a gradient associated with the acquired seismic data and the associated synthetic seismic data, and iteratively inverting a waveform associated with the exponentially encoded acquired seismic data and the exponentially encoded associated synthetic seismic data based on the gradient. An image of a subsurface location can be generated based on results of the iterative inversions.
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7.
公开(公告)号:US20190187313A1
公开(公告)日:2019-06-20
申请号:US16350083
申请日:2018-09-21
Applicant: PGS Geophysical AS
Inventor: Nizar Chemingui , Alejandro A. Valenciano Mavilio , Faqi Liu , Shaoping Lu
CPC classification number: G01V1/345 , G01V1/303 , G01V1/362 , G01V1/38 , G01V2210/32 , G01V2210/44 , G01V2210/51
Abstract: This disclosure describes processes and systems for generating a seismic image of a subterranean formation from recorded seismic data gathers obtained in a marine seismic survey of the subterranean formation. The seismic data comprises recorded pressure and vertical velocity wavefields that are used to separate the recorded pressure wavefield into upgoing and downgoing pressure wavefields. A seismic image is computed from the subterranean formation based on a product of the downgoing pressure wavefield and a migration operator applied to the upgoing pressure wavefield. The downgoing pressure wavefield is a boundary source wavefield and the upgoing pressure wavefield is boundary receiver wavefield of the migration operator. The seismic image is iteratively updated by computing a residual seismic image based on the upgoing pressure wavefield and adding the residual seismic image to the seismic image. The final seismic image displays increased illumination and reduced crosstalk artifacts compared to conventional seismic imaging techniques.
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公开(公告)号:US09689999B2
公开(公告)日:2017-06-27
申请号:US14550001
申请日:2014-11-21
Applicant: PGS Geophysical AS
Inventor: Didier B. P. Lecerf , Nizar Chemingui , Alejandro A. Valenciano Mavilio , Shaoping Lu
CPC classification number: G01V1/28 , G01V2210/1293 , G01V2210/1423 , G01V2210/56 , G01V2210/57
Abstract: Techniques are disclosed relating to geophysical analysis. In one embodiment, a method includes receiving seismic data for a geophysical formation recorded during a seismic survey using one or more seabed sensors and one or more sources. In this embodiment, the method includes determining a seismic gather for a location in the geophysical formation, modifying the seismic gather by interchanging source-receiver definitions for the seismic gather, and imaging the location using the modified gather. In this embodiment, the imaging uses higher-order reflections recorded in the seismic gather. In some embodiments, the method includes separating up-going and down-going wavefields and separately imaging using the up-going wavefield and the down-going wavefield.
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