Blended Seismic Trace Processing for Cross-Talk-Free Subsurface Imaging
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Solution Overview
Problem
Existing seismic data acquisition methods using simultaneous or blended sources result in cross-talk noise, making it difficult to separate individual shots and leading to unclear imaging of subsurface structures, which is costly and inefficient.
Innovation Solution
Record seismic data with different uncontaminated recording time lengths by using varying lags for seismic source actuations, allowing for the separation of traces into subgroups with consistent uncontaminated time lengths, and process these subgroups independently to generate a clear image of the subsurface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simultaneous source shooting is used to reduce acquisition time, then productivity increases, but source interference (cross-talk noise) worsens making it difficult to separate individual shots
Solution Approach 1:
The patent segments the contaminated seismic record into multiple portions, each associated with a different source. By dividing the record into time segments and using randomization codes, the system can separately process and reconstruct signals from individual sources even when they overlap in time, thus resolving the cross-talk problem while maintaining fast simultaneous acquisition
Solution Approach 2:
The patent applies randomization coding to the source signals before recording. This preliminary encoding allows the system to later separate and identify individual source contributions from the blended record, enabling fast simultaneous shooting without losing the ability to process individual shots
2Device complexity
If constant recording time is used for all traces, then device complexity is reduced, but imaging precision worsens for structures at different depths
Solution Approach 1:
The patent assigns different recording time lengths to different traces based on their specific characteristics. Traces contaminated by cross-talk at earlier times have shorter uncontaminated portions, while others have longer portions. This local differentiation optimizes the usable recording time for each trace according to its actual signal quality rather than applying a uniform time limit
Solution Approach 2:
The patent dynamically determines the uncontaminated recording time length for each trace based on when cross-talk arrives. Rather than using a fixed recording time for all traces, the system adapts the effective recording duration to each trace's contamination pattern, maximizing the use of clean signal data
Data Source
AI summary
A method for generating an image of a subsurface based on blended seismic data includes receiving the blended seismic data, which is recorded so that plural traces have uncontaminated parts with different uncontaminated recording time lengths, selecting plural subgroups (SG1, SG2) of traces so that each subgroup (SG1) includes only uncontaminated parts that have a same uncontaminated recording time length, processing the traces from each subgroup to generate processed traces, mapping the processed traces to a same sampling, combining the processed traces from the plural subgroups (SG1, SG2) to generate combined processed traces, and generating an image of a structure of the subsurface based on the combined processed traces.