Transient Electromagnetic Induced Polarization Field Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for electromagnetic data inversion are hindered by induced polarization effects, leading to distorted data and difficulty in separating pure electromagnetic and induced polarization fields, which affects the accuracy and credibility of inversion results, especially in low resistivity and high polarization underground structures.
Innovation Solution
A deep learning-based method using convolutional neural networks for field separation and multi-parameter information inversion, allowing for the extraction of pure electromagnetic and induced polarization fields, reducing inversion complexity and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the early data are used to obtain underground resistivity structure by three-dimensional inversion, then the resistivity structure can be obtained, but the calculation amount is large and the method is not suitable for all underground structure inversions
Solution Approach 1:
The patent performs three-dimensional inversion on early electromagnetic data first to obtain the underground resistivity structure before processing the polluted data. This preliminary action creates a reference model that enables subsequent efficient processing of polluted data through forward modeling and subtraction, avoiding the need to perform expensive three-dimensional inversion on all datasets.
2Measurement precision
If the pure electromagnetic response is obtained by three-dimensional forward modelling using resistivity information, then the pure electromagnetic response can be calculated, but the calculation amount is large
Solution Approach 1:
The patent uses the resistivity structure obtained from early data inversion to create a forward model that copies the geological structure. This model is then used to generate synthetic pure electromagnetic responses through forward modeling, which are subsequently subtracted from the polluted data to isolate the induced polarization response, avoiding direct inversion of polluted data.
3Measurement precision
If the induced polarization effects are removed as noise from electromagnetic data, then the data quality is improved, but the useful information contained in the data is also removed
Solution Approach 1:
Instead of removing induced polarization effects as noise, the patent extracts them as a separate useful signal. By subtracting the forward-modeled pure electromagnetic response from the polluted data, the method isolates the induced polarization response for separate analysis, preserving all useful information while enabling independent study of both electromagnetic and polarization properties.
4Loss of information
If the Cole-Cole model is used to inverse resistivity and polarizability information at the same time, then multi-parameter information is obtained, but the calculation amount is large and it is limited to one-dimensional inversion
Solution Approach 1:
The patent segments the inversion process into two independent parts: first inverting resistivity structure from early electromagnetic data, then inverting polarizability from the extracted induced polarization response. This segmentation avoids the complexity of simultaneous multi-parameter inversion while still achieving comprehensive parameter extraction through separate, specialized inversion steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves fast convergence, high prediction accuracy, and accurate separation of electromagnetic and induced polarization fields, enabling the precise inversion of physical and shape parameters of low-resistance polarization layers, consistent with actual drilling formation information.
Implementation Method 1
Based on the law of electromagnetic induction, the transient electromagnetic method realizes the detection of underground targets according to the resistivity difference of underground structures
Implementation Method 2
when there are low resistivity and high polarization bodies underground, such as sulfide minerals and carbonaceous tuff, the induced polarization effects will affect the electromagnetic induction field
Data Source
AI summary
Provided are a method and a system for transient electromagnetic-induced polarization field separation and multi-parameter information extraction. The method includes the following steps: obtaining electromagnetic data influenced by an induced polarization effect; performing a separating treatment of an induced polarization field and an electromagnetic field on the electromagnetic data influenced by the induced polarization effect to obtain a pure electromagnetic response field and a pure induced polarization response field; based on the pure electromagnetic response field and the pure induced polarization response field, respectively performing a multi-parameter information inversion to complete an extraction of geoelectric parameters. This system includes a data obtaining module, a field separation module and a parameter inversion module.