Multi-Sub Resistivity Tool Signal Processing
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Solution Overview
Problem
Current well logging technologies face challenges in accurately determining resistivity of downhole formations due to limitations in measuring tool face offsets and dogleg angles, which affect the depth of penetration and accuracy of electromagnetic signals during drilling operations.
Innovation Solution
A multi-sub rotational resistivity tool with modularized subs, featuring separate transmitter and receiver antennas, that accounts for tool face offsets and dogleg angles by emitting and detecting electromagnetic signals, allowing for deeper penetration and more accurate resistivity measurements through signal processing that corrects for these factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If electromagnetic signals are transmitted deeper into the formation, then the depth of penetration is improved, but the accuracy of measuring tool face offsets and dogleg angles deteriorates
Solution Approach 1:
The tool is divided into multiple subs, each with its own transmitter and receiver antennas. This segmentation allows for multiple measurement channels that can be processed independently and combined to achieve both deep penetration and high measurement precision through multi-channel signal processing
Solution Approach 2:
Signal processing techniques act as intermediaries between the electromagnetic signals and the final measurements. The processing system uses mathematical models and algorithms to correct for tool face offsets and dogleg angles, transforming raw signals into accurate formation resistivity measurements despite the challenges of deep penetration
2Measurement precision
If multiple subs with separate transmitter and receiver antennas are used, then the depth of penetration and measurement accuracy are improved, but the device complexity increases
Solution Approach 1:
Each sub in the multi-sub tool is designed as a universal module that can function as both a transmitter sub and a receiver sub. This multi-functionality reduces the need for completely separate components and allows for standardized designs that simplify manufacturing and assembly while maintaining measurement accuracy
Solution Approach 2:
The patent combines multiple antenna systems into an integrated multi-sub tool assembly. By merging the transmitter and receiver systems into a coordinated multi-sub structure with shared processing electronics and unified mechanical support, the overall device complexity is managed while achieving improved measurement capabilities
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 solution provides more accurate resistivity measurements, enabling proactive geosteering and increased hydrocarbon recovery by improving the depth of signal penetration and accounting for complex wellbore trajectories.
Implementation Method 1
determining a resistivity of a formation, based on a detection of angular electromagnetic signals by a receiver antenna on a first sub of a multi-sub resistivity tool during rotational operation in a wellbore within the formation, the angular electromagnetic signals emitted into the formation, prior to the detection, by a transmitter antenna on a second sub of the multi-sub resistivity tool
Data Source
AI summary
A method comprising determining a resistivity of a formation, based on a detection of angular electromagnetic signals by a receiver antenna on a first sub of a multi-sub resistivity tool during rotational operation in a wellbore within the formation, the angular electromagnetic signals emitted into the formation, prior to the detection, by a transmitter antenna on a second sub of the multi-sub resistivity tool, wherein the first sub and the second sub are separated apart such that the angular electromagnetic signals are to be transmitted deep into the formation, wherein determining the resistivity comprises curve-fitting and reproducing angular electromagnetic signals by the receiver antenna, and decoupling component signals based on fitting coefficients derived from the angular electromagnetic signals.