Pixel-Based Inversion for Real-Time Well Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current subsurface exploration techniques face challenges in accurately determining formation properties and well placement in real-time, particularly due to limitations in inversion methods used for processing electromagnetic measurements, which can lead to inaccuracies in geosteering decisions.
Innovation Solution
The development of pixel-based inversion techniques that use anti-symmetrized measurements and induction and propagation measurements to estimate formation resistivity and anisotropy at any angle, independent of mud type, allowing for minimally biased real-time interpretation without assuming a maximal number of layers, and incorporating adaptive regularization methods to improve inversion convergence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inversion methods are used to process electromagnetic measurements, then the processing can be performed with standard algorithms, but the accuracy of formation property determination and well placement is reduced
Solution Approach 1:
The patent applies anti-symmetrization to the electromagnetic measurement data before inversion processing. This asymmetric transformation of the measurement data improves the accuracy of formation property determination by reducing artifacts and enhancing the signal characteristics, while maintaining computational efficiency through a mathematically elegant transformation approach.
Solution Approach 2:
The patent transforms the measurement parameters through anti-symmetrization, changing the mathematical representation of the data. This parameter transformation improves inversion accuracy by emphasizing certain signal characteristics while suppressing others, leading to better formation property estimation without requiring fundamentally different inversion algorithms.
2Reliability
If real-time interpretation is performed without adaptive regularization, then the processing speed is maintained, but the inversion convergence and reliability are reduced
Solution Approach 1:
The patent implements adaptive regularization where the regularization parameter is dynamically adjusted during the inversion process based on the convergence behavior and data characteristics. This dynamic adaptation improves the reliability and robustness of inversion results by optimizing the trade-off between data fit and model stability, while maintaining real-time processing capability through efficient parameter update strategies.
Solution Approach 2:
The adaptive regularization mechanism uses feedback from the inversion process itself (convergence rate, data misfit, model stability) to adjust the regularization parameter in real-time. This feedback loop ensures that the inversion converges reliably while maintaining processing speed, as the regularization strength is optimized based on actual process performance rather than fixed predetermined values.
3Measurement precision
If assumption of maximal number of layers is made in inversion, then the inversion process is simplified, but the accuracy of resistivity profiles and anisotropy images is reduced
Solution Approach 1:
The patent uses anti-symmetrized measurements that inherently handle complex subsurface structures without requiring assumptions about the number of layers. The anti-symmetrization process segments the information content in a way that allows the inversion to naturally resolve the actual number of formation layers present, improving resistivity profile accuracy while avoiding the constraints and potential errors associated with predetermined layer assumptions.
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
These techniques enable more accurate and reliable real-time interpretation of subsurface formations, improving the precision of well placement and geosteering by providing detailed resistivity profiles and anisotropy images, reducing artifacts, and enhancing the robustness of inversion results.
Implementation Method 1
a transmitter antenna is energized by an alternating current to emit EM energy through the borehole fluid ('mud') and into the surrounding formation or formations
Implementation Method 2
The emitted energy interacts with the borehole and formation to produce signals that are detected and measured by one or more receiver antennas
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
A method is disclosed herein. The method includes disposing an electromagnetic logging tool in a borehole penetrating a formation, the electromagnetic logging tool being part of a drill string in the formation, the drill string having a drill bit. The method includes acquiring measurements using the electromagnetic logging tool. Further, the method includes using a processor, applying a pixel-based inversion to the acquired measurements to determine at least one formation property, wherein applying the pixel-based inversion includes using adaptive regularization.