Seismic First-Arrival Picking With Iterative Global Path Tracing
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Solution Overview
Problem
Existing seismic data processing methods rely heavily on accurate initial pilots for first arrival picking, which can be challenging, especially in unexplored or complex subsurface regions, leading to inaccuracies in determining seismic velocity models and seismic images.
Innovation Solution
An iterative method using global path tracing with a pilot that iteratively creates preconditioned gathers, determines differential pilots, and increments the pilot to achieve a total picked first arrival, allowing for accurate first arrival picking without reliance on an initial accurate pilot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional first arrival picking methods are used, then the process requires accurate initial pilots, but this leads to inaccuracies in complex subsurface regions
Solution Approach 1:
The patent segments the first arrival picking process into multiple iterative stages: initial pilot determination, preconditioned gather creation, differential pilot determination via global path tracing, and incremental updates. Each stage refines the previous results, breaking down the complex problem of accurate first arrival picking in challenging subsurface regions into manageable iterative steps that progressively improve accuracy without requiring a perfectly accurate initial pilot.
Solution Approach 2:
The patent implements a dynamic iterative process where the pilot is continuously updated through multiple cycles of global path tracing and differential determination. Rather than relying on a static initial pilot, the system dynamically adapts the pilot estimates through successive iterations, allowing the method to handle complex subsurface variations that would challenge static or single-pass approaches.
2Measurement precision
If iterative global path tracing is performed, then first arrival picking accuracy improves, but computational complexity increases
Solution Approach 1:
The patent performs preliminary actions by determining an initial pilot (even if not perfectly accurate) and creating preconditioned gathers before the main iterative global path tracing process. This preliminary setup organizes the data and provides starting estimates that guide the subsequent iterative refinement, making the complex computational process more manageable and efficient by preparing the groundwork in advance.
Solution Approach 2:
The patent incorporates feedback mechanisms where each iterative cycle uses the results from the previous cycle to inform the next. The differential pilot determined through global path tracing feeds back into updating the total picked first arrival, which then becomes the basis for the next iteration. This feedback loop allows the system to progressively improve accuracy while the iterative structure helps manage computational complexity by building upon previous results rather than recalculating from scratch.
Data Source
AI summary
Systems and methods for automated first arrival picking are disclosed. The method includes obtaining a seismic dataset composed of a plurality of seismic gathers and determining a pilot for each gather, where the pilot includes a position on an ordinate axis for each seismic trace representing a first arrival. The method continues iteratively until a stopping criterion is met by creating a preconditioned gather using the pilot, determining a differential pilot using global path tracing subject to a constraint and incrementing the pilot using the differential pilot to create a total picked first arrival. Once the stopping criterion has been met, the method further includes determining a final picked first arrival based on the total picked first arrival, determining a seismic velocity model from the final picked first arrival using a tomographic inversion and creating a seismic image using the seismic velocity model and the seismic dataset.