Downhole Sliding Sleeve Position Sensing for Misalignment Correction
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Solution Overview
Problem
Existing downhole sliding sleeve valve assemblies in oil and gas wells face challenges in accurately determining the relative position of the sleeve and housing, leading to misalignment errors and inefficiencies in fluid flow control.
Innovation Solution
A downhole valve assembly with a sensor assembly comprising first and second primary sensors disposed at different circumferential positions around the axis, which detect markers on the sleeve or housing, producing an output signal by processing signal components to correct for misalignment and provide accurate position information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single sensor is used to detect the position of the sleeve relative to the housing, then the device complexity is reduced, but the measurement precision deteriorates due to misalignment errors
Solution Approach 1:
The sensor assembly is segmented into multiple primary sensors (at least two) positioned at different circumferential locations around the sleeve. Each sensor independently detects the position of the sleeve relative to the housing, and their signals are processed together to determine the average position. This segmentation allows cancellation of misalignment errors while maintaining measurement precision without requiring a single complex high-precision sensor.
2Measurement precision
If circumferentially spaced sensors are used to correct misalignment errors, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The signals from multiple primary sensors are merged through processing circuitry that calculates the average position information. By combining the outputs of sensors at different circumferential positions, the system achieves error correction for misalignment, bending, and out-of-round conditions. This merging approach improves measurement precision while keeping each individual sensor simple and the overall assembly manageable.
3Reliability
If traditional position detection methods are used, then the device complexity is low, but the reliability deteriorates due to susceptibility to misalignment and environmental factors
Solution Approach 1:
The sensor assembly provides continuous feedback on the position of the sleeve relative to the housing by processing signals from multiple primary sensors. This feedback mechanism enables real-time detection of position changes and correction for misalignment errors, improving the reliability of position detection. The system continuously monitors and adjusts for environmental factors such as bending and out-of-round conditions through the combined sensor readings.
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 effectively corrects for misalignment errors, ensuring precise control of fluid flow by providing accurate position information, reducing errors from misalignment, bending, or out-of-round tubes, and allowing for reliable operation in various fluid media.
Implementation Method 1
the first and second primary sensors comprise inductive proximity sensors
Data Source
AI summary
A downhole valve assembly comprises a sleeve concentric with a housing and movable relative to a port through the housing to control flow of fluid through the port. A sensor assembly provides indicates the relative positions of the sleeve and housing, and comprises first and second sensors on e.g. the housing which detect markers on e.g. the sleeve. The sensor outputs are produced by processing (e.g. combining, integrating, summing, subtracting or otherwise processing) the signal components of each of the first and second sensors to correct for misalignment of the sleeve with the housing. The sensor output provides position information for more than one plane, and the output signal therefore allows for correction of errors in the position information arising from misalignment of the sleeve with the housing.