2D Pixel-Based Inversion for Geosteering Accuracy
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Solution Overview
Problem
Current well placement techniques using resistivity measurements for geosteering are limited by the accuracy of inversion methods, which often rely on one-dimensional approximations, leading to errors and noise sensitivity, especially when modeling complex subterranean formations with features like faults.
Innovation Solution
The implementation of a two-dimensional pixel-based inversion method that processes electromagnetic data to create a 2D formation model by discretizing the formation into pixels, using regularization techniques to minimize errors and model complex features accurately, allowing for real-time well placement and reservoir characterization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If one-dimensional inversion methods are used for geosteering, then the processing is simpler and faster, but the accuracy and reliability of formation modeling deteriorates due to errors and noise sensitivity
Solution Approach 1:
The patent transitions from one-dimensional inversion methods to two-dimensional pixel-based inversion methods. This dimensional change allows the system to model complex subterranean formations with faults and variations more accurately while maintaining computational efficiency through algorithmic optimizations.
2Device complexity
If one-dimensional inversion methods are used, then the computational complexity is lower, but the ability to model complex features like faults deteriorates
Solution Approach 1:
By implementing two-dimensional pixel-based inversion, the system gains the capability to model complex geological features such as faults and formation variations that cannot be adequately represented by one-dimensional methods, while managing computational complexity through efficient algorithms.
Solution Approach 2:
The formation is divided into discrete pixels in a two-dimensional grid, allowing complex features to be modeled through spatial distribution of resistivity values across multiple pixels, enhancing the system's ability to represent geological complexity.
3Measurement precision
If two-dimensional pixel-based inversion is implemented, then the accuracy and detail of formation modeling improves, but the computational complexity and processing time increases
Solution Approach 1:
The patent accepts increased computational complexity as a necessary trade-off for achieving superior formation modeling accuracy through two-dimensional pixel-based inversion, which provides detailed spatial characterization of subsurface properties.
Solution Approach 2:
The system optimizes computational parameters such as pixel dimensions, inversion regularization, and processing algorithms to balance the increased complexity of 2D inversion with practical processing requirements, enabling real-time or near-real-time application.
4Reliability
If two-dimensional pixel-based inversion is used, then noise sensitivity is reduced, but the processing requirements and computational resources increase
Solution Approach 1:
Two-dimensional pixel-based inversion provides redundant spatial information that helps distinguish signal from noise, reducing noise sensitivity through the additional dimensional constraint, while computational resources are managed through optimized algorithms.
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
This approach reduces errors and noise sensitivity, providing a more accurate and detailed 2D formation model that enhances geosteering precision and reservoir characterization, enabling better decision-making during drilling operations.
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. As used herein, 'formation' may refer to a single layer, multiple layers, faults, unconformities, geological bodies, and/or oil-water contacts. 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
AI summary
Methods and systems for characterizing subterranean formations are described herein. One method includes performing electromagnetic logging measurements along a portion of a borehole traversing the subterranean formation using an electromagnetic logging tool to obtain electromagnetic data. The method also includes processing the electromagnetic data to determine a plurality of one dimensional formation models associated with the portion of the borehole. A two dimensional pixel grid is determined using the plurality of one dimensional formation models. The method further includes determining a two dimensional formation model for the subterranean formation by performing an inversion of the electromagnetic data using the two dimensional pixel grid. The methods and systems described herein can be used to steer a bottom-hole assembly during well placement.