Seismic Crosstalk Attenuation via Wavefield Decomposition

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Solution Overview

Problem

Current marine seismic survey techniques face challenges in accurately imaging subsurface formations due to the generation of crosstalk, particularly causal and anti-causal crosstalk, which can lead to false indications of wavefield phases and noise in seismic images, hindering the effective use of multiple wavefields in seismic imaging.

Innovation Solution

The proposed solution involves predicting and attenuating causal and anti-causal crosstalk through advanced wavefield decomposition and processing techniques, allowing for the inclusion of multiple wavefields in seismic imaging without introducing noise, by modeling seismic sources and receivers as point sources and using Green's functions to simulate wavefield propagation and migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If multiple wavefields are included in seismic imaging to improve information content, then the quantity of useful information increases, but crosstalk noise is generated that degrades image quality

Engineering Contradiction:
Improveinformation from multiple wavefieldsVSAvoidcrosstalk noise
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent segments the total wavefield into distinct components (primaries, multiples, causal crosstalk, anti-causal crosstalk) through wavefield decomposition. By separating these components mathematically, the method enables selective attenuation of harmful crosstalk while preserving useful primary and multiple wavefield information for improved seismic imaging.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent converts the harmful crosstalk noise into a predictable and removable component. By modeling and predicting causal and anti-causal crosstalk based on the observed data, the method transforms the previously harmful interference into a structured element that can be systematically attenuated, thereby converting a disadvantage into a controllable parameter.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If advanced wavefield decomposition and processing techniques are applied to predict and attenuate crosstalk, then crosstalk attenuation improves, but processing complexity increases

Engineering Contradiction:
Improvecrosstalk attenuationVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by predicting causal and anti-causal crosstalk before final image assembly. The method pre-processes the wavefield data to estimate and remove crosstalk components in advance, which simplifies the overall processing workflow compared to attempting to remove crosstalk after image formation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method employs feedback mechanisms where the predicted crosstalk is iteratively refined and subtracted from the total wavefield. This feedback loop allows the processing system to continuously improve the accuracy of crosstalk attenuation while maintaining a systematic approach to managing processing complexity.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables the creation of more accurate seismic images by reducing crosstalk, allowing for the retention of valuable information from multiple wavefields, thereby improving the resolution and reliability of subsurface imaging in marine seismic surveys.

Implementation Method 1

Each acoustic signal is essentially a sound wavefield that travels down through the water and into the subterranean formation

Methodology Applied
Scientific EffectAcoustic wave propagation: Sound

Implementation Method 2

At each interface between different types of rock, a portion of the wavefield may be refracted, and another portion may be reflected, which may include some scattering, back toward the body of water

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The wavefield separation may separate the wavefield into a down-going wavefield and an up-going wavefield

Methodology Applied
Scientific EffectWavefield decomposition:

Implementation Method 4

by modeling seismic sources and receivers as point sources and using Green's functions to simulate wavefield propagation and migration

Methodology Applied
Scientific EffectGreen's function modeling:

Data Source

PatentEP3056928B1Crosstalk attenuation for seismic imaging
Publication Date: 2020.11.18 PGS GEOPHYSICAL AS
  • EP3056928B1 patent drawingFigure 1
  • EP3056928B1 patent drawingFigure 2
  • EP3056928B1 patent drawingFigure 3

AI summary

Crosstalk attenuation for seismic imaging can include creation of a seismic image based on seismic data including multiples. The seismic image can include causal crosstalk and anti-causal crosstalk. Causal crosstalk and anti-causal crosstalk can be predicted based on the seismic data. The predicted causal crosstalk and the predicted anti-causal crosstalk can be attenuated from the seismic image.