Seismic Guided Electromagnetic Inversion for Resistivity Map Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing geophysical surveying techniques face challenges in integrating electromagnetic inversions and seismic stratigraphic structures due to differences in resolution, leading to a lack of alignment between resistivity and seismic images of subsurface properties.
Innovation Solution
A method is developed to form a geologic map by obtaining seismic stratigraphic structures, determining potential resistivity boundaries, and performing iterative inversion processes on electromagnetic data sets using computer processing systems, where resistivity boundaries from seismic data are used to confine and refine resistivity maps, ultimately resolving a geologic map for identifying resource accumulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If electromagnetic inversion is performed independently without seismic guidance, then electromagnetic data processing is simpler, but the alignment and accuracy of resistivity boundaries with seismic stratigraphic structures deteriorates
Solution Approach 1:
The method performs preliminary extraction of seismic stratigraphic structures and determination of seismic boundaries before conducting electromagnetic inversion. These pre-determined seismic boundaries serve as constraints during the inversion process, ensuring that the final resistivity model aligns with the high-resolution seismic stratigraphy while maintaining a manageable inversion workflow
Solution Approach 2:
The patent introduces seismic boundaries as an intermediary constraint between the electromagnetic data and the inversion process. These seismic boundaries act as a mediator that guides the electromagnetic inversion to produce resistivity models that are consistent with both the electromagnetic measurements and the seismic stratigraphic framework
2Measurement precision
If seismic guidance is integrated into electromagnetic inversion, then alignment and accuracy of resistivity boundaries with seismic structures is improved, but device complexity and processing complexity increases
Solution Approach 1:
The method segments the integrated inversion process into distinct, manageable steps: (1) extracting seismic stratigraphic structures from seismic data, (2) determining seismic boundaries from the extracted structures, (3) performing electromagnetic inversion with these boundaries as constraints. This segmentation reduces overall system complexity by breaking down the complex integrated process into sequential, independently implementable stages
Solution Approach 2:
By pre-determining seismic boundaries and stratigraphic structures before electromagnetic inversion, the method prepares constraint templates that simplify the inversion process. This preliminary preparation reduces the computational complexity during the actual inversion by providing fixed boundary conditions that guide the optimization algorithm
3Productivity
If low resolution electromagnetic inversion is performed, then electromagnetic data processing is faster and simpler, but the resolution and detail of subsurface resistivity imaging deteriorates
Solution Approach 1:
The method changes the parameter constraints during inversion by incorporating seismic boundary information as additional constraints. This modifies the inversion problem from an unconstrained or loosely constrained optimization to a tightly constrained problem where the resistivity model must satisfy both electromagnetic data fit and seismic boundary alignment, thereby improving resolution without proportionally increasing processing time
Data Source
AI summary
Methods of forming a geologic map usable for identifying prospective resource accumulations beneath the earth-surface are disclosed herein. The methods include obtaining a seismic stratigraphic structure of a subsurface region of the earth, determining a plurality of potential resistivity boundaries from the seismic stratigraphic structure, obtaining an electromagnetic data set resulting from an electromagnetic data acquisition of the subsurface region, recovering a resistivity map of the subsurface region by performing an inversion process guided by the seismic information, and resolving a geologic map from the resistivity map.