Geophysical inversion using sparse modeling
AssigneePGS Geophysical AS
InventorsLars Erik Magnus Björnemo, Carl Joel Gustav Skogman
Life of this patent
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Abstract
Methods of geophysical modeling and inversion are disclosed. A sparse domain is defined for a geophysical model, over which a sparse model result is computed. A full model result is then resolved by interpolation over the sparse domain. The full model result may be used as the forward modeling result in a geophysical inversion process. Reconstruction error, or model error, or both may be used to adjust the sparse domain, the model, or the geophysical basis of the model.
Claims18
A method of modeling a geophysical system, comprising:
- defining a geophysical model of an area of the earth;
- defining a domain for the geophysical model including a physical domain and a parameter domain, wherein the parameter domain comprises frequency, offset, and source position and receiver position;
- defining a sparse domain for the geophysical model, wherein the sparse domain has a sparse parameter domain that is a subset of the parameter domain, wherein a density of points in the sparse parameter domain
- declines with a distance between the source position and the receiver position;
- determining a geophysical basis of the geophysical system;
- computing a sparse model result based on the sparse domain and the geophysical basis;
- and
- resolving a model result from the sparse model result by interpolation.
A method of determining physical properties of an area of the earth, comprising:
- obtaining a geophysical survey of an area of the earth;
- defining a geophysical model of the area of the earth;
- defining a domain of the geophysical model including a physical domain and a parameter domain, wherein the parameter domain comprises frequency, offset, and source position and receiver position;
- defining a sparse domain including the physical domain and a sparse parameter domain that is a subset of the parameter domain, wherein a density of points in the sparse parameter domain
- declines with a distance between the source position and the receiver position;
- defining a geophysical basis for the area of the earth;
- computing a sparse model result based on the sparse domain using the geophysical model;
- resolving a model result from the sparse model result by interpolation;
- defining a model error by comparing the model result to the geophysical survey;
- and
- changing the geophysical basis based on the model error.
A method of modeling a geophysical system, comprising:
- defining a geophysical model of an area of the earth;
- defining a domain for the geophysical model including a physical domain and a parameter domain, wherein the parameter domain comprises frequency, offset, and source position and receiver position;
- defining a sparse domain for the geophysical model, wherein the sparse domain has a sparse parameter domain that is a subset of the parameter domain, wherein a density of points in the sparse parameter domain varies with water depth as a function of the source position and the receiver position;
- determining a geophysical basis of the geophysical system;
- computing a sparse model result based on the sparse domain and the geophysical basis;
- and
- resolving a model result from the sparse model result by interpolation.
A method of determining physical properties of an area of the earth, comprising:
- obtaining a geophysical survey of an area of the earth;
- defining a geophysical model of the area of the earth;
- defining a domain of the geophysical model including a physical domain and a parameter domain, wherein the parameter domain comprises frequency, offset, and source position and receiver position;
- defining a sparse domain including the physical domain and a sparse parameter domain that is a subset of the parameter domain, wherein a density of points in the sparse parameter domain varies with water depth as a function of the source position and the receiver position;
- defining a geophysical basis for the area of the earth;
- computing a sparse model result based on the sparse domain using the geophysical model;
- resolving a model result from the sparse model result by interpolation;
- defining a model error by comparing the model result to the geophysical survey;
- and
- changing the geophysical basis based on the model error.
Dependencies are inferred from the claim text.