Pre-Stack Attenuation Analysis for Accurate Gas-Bearing Prediction
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Solution Overview
Problem
Existing gas-bearing prediction methods based on pre-stack seismic data face challenges such as multiplicity of solutions, difficulty in constructing low-frequency models, unstable wavelets, and the impact of elastic parameter properties, leading to inaccurate predictions.
Innovation Solution
A method that constructs a pre-stack attenuation attribute using dominant incident angles and frequency double-domain attenuation, capturing attenuation gradients from pre-stack seismic data to form a gas-bearing sensitive factor, overcoming the limitations of conventional inversion methods by directly analyzing seismic data within specific angle ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pre-stack inversion is applied to construct elastic parameters, then gas-bearing prediction can be performed, but the prediction accuracy is reduced due to multiplicity of solutions and unstable wavelets
Solution Approach 1:
The patent extracts only the necessary post-stack attenuation information from the pre-stack seismic data, rather than performing full inversion. By extracting attenuation attributes directly from pre-stack gathers within specific incident angle ranges, the method avoids the multiplicity of solutions and wavelet instability problems inherent in complete inversion processes while still obtaining gas-bearing prediction capabilities.
Solution Approach 2:
The patent introduces attenuation attributes as an intermediary between pre-stack seismic data and gas-bearing prediction. Instead of directly inverting elastic parameters, the method uses attenuation attributes calculated from pre-stack gathers as a mediator, which simplifies the inversion process and reduces sensitivity to wavelet variations and solution multiplicity.
2Reliability
If conventional pre-stack inversion is used, then elastic parameters can be obtained, but the construction of low-frequency models conforming to geological understanding becomes difficult
Solution Approach 1:
The patent extracts attenuation information directly from pre-stack seismic data without requiring complex low-frequency model construction. By focusing on attenuation attributes rather than full elastic parameter inversion, the method obtains gas-bearing prediction capability while avoiding the complexity of constructing geologically consistent low-frequency models.
3Quantity of substance
If full pre-stack inversion is performed, then comprehensive elastic parameters are obtained, but the impact of elastic parameter properties dominates over gas-bearing differences, reducing prediction accuracy
Solution Approach 1:
The patent extracts specifically the attenuation information from pre-stack seismic data, separating it from other elastic parameter effects. By calculating attenuation attributes within dominant incident angle ranges, the method isolates gas-bearing related signals from the dominant effects of elastic parameter variations, thereby improving prediction precision while retaining useful pre-stack information.
Solution Approach 2:
The patent applies local quality by calculating attenuation attributes within specific dominant incident angle ranges rather than using the entire angular spectrum. This localized approach enhances the sensitivity to gas-bearing characteristics while reducing the influence of elastic parameter properties that manifest differently across various angle ranges.
4Ease of manufacture
If post-stack attenuation methods are used, then the processing is mature and straightforward, but the application effects are limited due to using only post-stack information
Solution Approach 1:
The patent merges the advantages of post-stack attenuation calculation simplicity with pre-stack data information richness. By calculating attenuation attributes from pre-stack gathers (which contain both amplitude and attenuation information) using methods similar to post-stack processing, the approach maintains implementation ease while significantly improving gas-bearing prediction effectiveness through access to additional pre-stack information.
Data Source
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AI summary
Provided in the present disclosure are a gas-bearing prediction method and apparatus based on dominant incident angle and frequency double-domain attenuation. In the method, an attenuation attribute is captured from a pre-stack gather within a range of dominant incident angles, the attenuation attribute being an improved high-frequency attenuation gradient attribute; and a gas-bearing sensitive factor is formed to complete gas-bearing prediction. Further provided in the present disclosure are a prediction apparatus, a computer readable storage medium and an electronic device.