Amplitude Compensation in Reverse Time Migration Gathers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seismic imaging techniques, such as reverse time migration, often result in inaccurate amplitude compensation, leading to poor image quality of subsurface reservoirs and geological structures, especially in complex geological environments, due to the lack of numerical stability and high computing costs.
Innovation Solution
A method and system for amplitude compensation in reverse time migration (RTM) gathers using amplitude versus offset (AVO) and amplitude versus angle (AVA) techniques, which involves generating synthetic seismograms, estimating scalar correction filters, and interpolating them to produce amplitude-compensated gathers that can be used for AVO/AVA analysis, thereby improving image fidelity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional reverse time migration is used for seismic imaging, then computational cost is reduced, but amplitude compensation accuracy deteriorates
Solution Approach 1:
The patent pre-calculates and stores amplitude compensation operators during an initialization phase using ray tracing and Q-model data. These pre-computed operators are then applied during RTM imaging without requiring real-time complex calculations, thus achieving accurate amplitude compensation while maintaining computational efficiency during the actual imaging process
Solution Approach 2:
The patent compensates for amplitude distortions and numerical instability issues before they affect the final imaging results by applying pre-computed correction operators. This beforehand cushioning approach prevents amplitude errors from accumulating during the RTM process, ensuring accurate AVO/AVA analysis without increasing computational cost
2Manufacturing precision
If advanced amplitude compensation techniques are applied to RTM gathers, then image quality improves, but computational complexity increases
Solution Approach 1:
The patent divides the amplitude compensation process into separate, independent steps: (1) ray tracing to compute travel times and amplitudes, (2) Q-model-based attenuation correction, (3) illumination compensation, and (4) application during RTM. This segmentation allows each component to be optimized independently and applied efficiently without requiring complex integrated computations
Solution Approach 2:
The patent introduces pre-computed amplitude compensation operators as an intermediary between the raw RTM gathers and the final migrated image. These operators, calculated beforehand using ray tracing and Q-models, mediate the amplitude corrections without requiring complex real-time computations during the imaging process itself
3Measurement precision
If numerical stability is improved in RTM, then amplitude accuracy improves, but processing time increases
Solution Approach 1:
The patent performs all numerically intensive stability corrections and amplitude calculations in advance during an initialization phase. By pre-computing the compensation operators using ray tracing and Q-models, the actual RTM imaging process applies these corrections efficiently without requiring additional processing time during the main imaging workflow
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A method of geophysical exploration in a seismic survey includes acquiring a set of seismic traces based on seismic data obtained by a seismic receiver, responsive to seismic energy reflected from a subsurface geology. Additional steps include performing reverse time migration on the seismic traces using a velocity model that represents velocity of the seismic energy propagating through the seismic medium. The migrated gathers have an amplitude based at least in part on the migration, which can be corrected by computing synthetic seismograms to provide compensated gathers. Amplitude versus offset and/or amplitude versus angle analysis can be performed on the compensated gathers, in order to generate a seismic image of subsurface structures in the survey area.