Orthogonal Source and Receiver Encoding for Seismic Inversion
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Solution Overview
Problem
Seismic full wavefield inversion is computationally expensive due to the need for numerous simulations, especially in iterative inversion methods, which are impractical for large-scale problems due to high computational costs and loss of accuracy when combining sources.
Innovation Solution
A computer-implemented method that encodes geophysical data from multiple sources using orthogonal or pseudo-orthogonal encoding functions, allowing simultaneous inversion of encoded gathers to reduce computational effort and maintain accuracy by making receivers insensitive to inactive sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If iterative inversion is used to improve model accuracy, then manufacturing precision is improved, but productivity deteriorates due to high computational costs
Solution Approach 1:
The patent combines multiple source gathers into a single simultaneous encoded gather, merging data from multiple sources that would traditionally require separate simulations. This reduces the number of forward and adjoint simulations needed in iterative inversion, improving computational efficiency while maintaining model accuracy through orthogonal encoding that preserves source information.
Solution Approach 2:
The patent applies orthogonal encoding to source gathers before combining them, performing a preliminary transformation that enables subsequent efficient processing. This preliminary encoding action allows the combined gather to be processed as a single unit while still enabling accurate separation and inversion of individual source contributions during iterative inversion.
2Productivity
If multiple sources are combined to reduce computational cost, then productivity is improved, but manufacturing precision deteriorates due to loss of accuracy
Solution Approach 1:
The patent transforms the data representation by applying orthogonal encoding functions to the source gathers, changing the parameter space in which the data is processed. This parameter transformation allows multiple sources to be combined while preserving the information needed for accurate inversion, as the orthogonal encoding maintains source distinguishability in the transformed domain.
3Productivity
If simultaneous source inversion is used to improve productivity, then productivity is improved, but manufacturing precision deteriorates when fixed-receiver assumption is not satisfied
Solution Approach 1:
The patent applies receiver-specific encoding functions that are tailored to each receiver's illumination pattern. This local customization of encoding ensures that each receiver's data is optimally processed according to its specific geometric relationship with sources, maintaining accuracy even when the fixed-receiver assumption is not satisfied, while still enabling efficient simultaneous source inversion.
Data Source
AI summary
Method for performing simultaneous encoded-source inversion of geophysical data to estimate parameters of a physical property model (41), especially adapted for surveys without fixed-receiver acquisition geometry, such as marine seismic surveys with moving source and receivers. The encoding functions (32) used on the sources to generate one or more simultaneous encoded-source gathers of data (35), as well as to simulate the same (34), are orthogonal or pseudo-orthogonal with respect to cross-correlation. In addition, receivers are also encoded, with the receiver encoding being designed to make a given receiver less sensitive to sources to which it was not listening during the survey (38). The encoding functions may be temporal bandpass filters differing one from another by central frequency, phase, or both. Efficiency of the method may be further improved by grouping several sources into a super-source, grouping the corresponding gathers into a super-gather, and then applying the above encoding strategy.