Seismic Image Gather Computation Using Segmented Depth Migration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current seismic data processing methods, particularly in the computation of common image gathers (CIGs) in the angle domain, are computationally expensive and require significant memory, especially for 3D cases, and often lack the resolution and azimuth information needed for accurate subsurface analysis.

Innovation Solution

A process involving depth migration techniques using cross-correlation and gradient-based imaging conditions to generate CIGs, with amplitude correction and illumination compensation, allowing for efficient computation and storage of seismic data, applicable to both isotropic and anisotropic media.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional depth migration techniques are used to compute common image gathers (CIGs) in the angle domain, then subsurface imaging is achieved, but computational cost and memory requirements become excessively high, especially for 3D cases

Engineering Contradiction:
Improvesubsurface imaging qualityVSAvoidcomputational cost
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent segments the CIG computation into two separate images: one computed using cross-correlation imaging condition and another using gradient-based imaging condition. These segmented images are then combined to form the final CIGs, allowing efficient computation while maintaining imaging quality in both isotropic and anisotropic media

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the imaging condition parameter from a single conventional approach to a dual-approach system that switches between cross-correlation and gradient-based conditions. This parameter change enables the system to adapt to different media types (isotropic vs. anisotropic) and reduces computational burden while preserving subsurface imaging accuracy

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If conventional depth migration techniques are used to compute common image gathers (CIGs) in the angle domain, then subsurface imaging is achieved, but memory requirements become excessively high, especially for 3D cases

Engineering Contradiction:
Improvesubsurface imaging qualityVSAvoidmemory requirements
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the CIG computation into two separate images that are computed and stored independently. By processing and combining these segmented results rather than storing complete CIGs during computation, the system significantly reduces memory requirements while maintaining imaging quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts only the essential image information needed for final CIG formation by computing separate cross-correlation and gradient-based images. This extraction approach avoids storing redundant intermediate data structures, thereby reducing memory consumption while preserving the necessary subsurface imaging quality

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If conventional migration techniques are used, then CIGs can be generated, but they lack the resolution and azimuth information needed for accurate subsurface analysis

Engineering Contradiction:
Improvesubsurface analysis accuracyVSAvoidazimuth information and resolution
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent performs preliminary computation of two distinct images (cross-correlation and gradient-based) before combining them to form the final CIGs. This preliminary action ensures that azimuth information and high-resolution details are captured in each separate image computation, preventing information loss that would occur in conventional single-step migration

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the imaging approach to include both cross-correlation and gradient-based conditions, which preserves azimuth information and enhances resolution. This parameter change allows the system to maintain accurate subsurface analysis capabilities by capturing directional information that conventional techniques would lose

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2920615B1Process for creating image gathers
Publication Date: 2019.07.24 TOTALENERGIES SE
  • EP2920615B1 patent drawingFigure 1
  • EP2920615B1 patent drawingFigure 2
  • EP2920615B1 patent drawingFigure 3A~3C

AI summary

The process of obtaining seismic data includes deploying a seismic energy source and seismic receivers, actuating the source, and detecting seismic energy resulting therefrom at the receivers. The process further includes digitally sampling seismic energy detected at the receivers indexed with respect to time to form a plurality of traces and sorting the traces to form a plurality of shot gathers.