Seismic Surface-Consistent Correction via Model Constraints

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Solution Overview

Problem

Current seismic data processing methods face challenges in correcting long wavelength components of surface consistent equations, particularly when near-surface variations occur over large areas, leading to indeterminacies and difficulties in isolating surface consistent variations.

Innovation Solution

A method and system for constraining surface consistent inversions in seismic data processing, which involves transforming radial and vertical components into primary and ghost components, determining S-wave speed, and using these to correct for near-surface issues by constraining inversions, allowing for more deterministic approaches to deal with near-surface corrections in converted-wave processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional surface consistent inversion is used, then short wavelength components can be corrected, but long wavelength components remain indeterminate and difficult to isolate

Engineering Contradiction:
Improvecorrection precisionVSAvoidinversion complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the surface consistent inversion into two distinct parts: a data-driven component that handles short wavelength variations using conventional inversion, and a model-constrained component that handles long wavelength variations using geological models. This segmentation allows each component to be optimized independently, resolving the indeterminacy of long wavelength solutions while maintaining the precision corrections for short wavelength components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the approach by introducing external constraints from geological models (velocity models, density models, topography) as additional parameters in the inversion process. These constraints provide the missing information for long wavelength components, transforming the underdetermined system into a well-constrained one without sacrificing the data-driven accuracy for shorter wavelengths.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If smoothing is applied to CDP term, then long wavelength resolution improves, but the method requires iterative processing and introduces constraints on the CDP term

Engineering Contradiction:
Improvelong wavelength resolutionVSAvoidprocessing efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary action by incorporating geological model constraints before the inversion process begins. These pre-existing models provide the long wavelength framework in advance, eliminating the need for iterative smoothing of the CDP term and reducing the processing steps required to achieve long wavelength resolution.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multi-grid method is used, then long wavelength resolution improves, but the computational complexity increases

Engineering Contradiction:
Improvelong wavelength resolutionVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces geological models as intermediary constraints that mediate between the seismic data and the inversion solution. These models act as a bridge providing the long wavelength information without requiring the complex multi-grid computational approach, thereby achieving long wavelength resolution with reduced computational complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2755059B1Seismic data processing including data-constrained surface-consistent correction
Publication Date: 2021.11.03 CGG SERVICES SAS
  • EP2755059B1 patent drawingFigure 1
  • EP2755059B1 patent drawingFigure 2
  • EP2755059B1 patent drawingFigure 3

AI summary

Methods and systems for constraining surface consistent amplitude corrections are described. An amplitude map generated from pre-stack or post-stack seismic data can constrain, through the bin term, the surface consistent inversion. The methods and systems provide a solution to correct for wavelength and regional anomalies associated with heterogeneous near surface or buried velocity variations above the target horizon. The methods and systems can be used for 2D, 3D, 4D surveys or for a merge of different surveys.