Magnetic Sensor Array for Downhole Positioning
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Solution Overview
Problem
Traditional downhole tools for oil and gas production, such as sliding sleeve separation tools, lack precise positioning and movement measurement capabilities due to complex electronics and limited temperature tolerance of magnetic sensors, making them unreliable in harsh subterranean environments.
Innovation Solution
A magnetic sensor array with Reed switches and a PCB-less design, actuated by a magnetic field, provides accurate real-time position indication and is robust against extreme conditions, using a conductor member with insulation and circumferentially spaced magnetic sensors, eliminating the need for field strength calibration and operating effectively up to 300°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If Hall sensors are used for position detection, then position measurement capability is provided, but the maximum operating temperature is limited to 150°C
Solution Approach 1:
The patent replaces electronic Hall sensors with a magnetic sensor array using permanent magnets and reed switches. This substitution eliminates the temperature limitation of Hall sensors (150°C) by using a magnetic field-based detection system that operates reliably at temperatures up to 300°C, significantly improving operational reliability in high-temperature downhole environments.
Solution Approach 2:
The patent changes the operating parameter range by selecting permanent magnets with specific remanence characteristics and spacing them at optimized intervals. This allows the magnetic sensor array to maintain reliable operation across extended temperature ranges (up to 300°C) compared to conventional Hall sensors, addressing the temperature limitation while preserving detection capability.
2Ease of operation
If PCBs and electronic components are used to drive magnetic sensors, then sensor operation is enabled, but device complexity and space requirements increase
Solution Approach 1:
The patent extracts and eliminates the PCB and associated electronic driving components from the system. By using permanent magnets that generate their own magnetic fields and reed switches that require no external power or complex electronics to operate, the system removes the source of complexity and space requirements while maintaining full sensor operation capability.
Solution Approach 2:
The magnetic sensor array employs permanent magnets that self-generate magnetic fields and reed switches that automatically respond to field changes without requiring external power supplies, signal amplification, or filtering electronics. This self-service approach eliminates complex electronic components while enabling complete sensor operation, reducing both device complexity and space requirements.
3Measurement precision
If permanent magnets are used for magnetic field generation, then position detection is enabled, but magnetic flux density decreases at high temperatures
Solution Approach 1:
The patent applies preliminary magnetization treatment to the permanent magnets during assembly, ensuring they achieve optimal magnetic strength before deployment. Additionally, the magnets are positioned and spaced in advance to compensate for expected thermal effects, ensuring consistent position detection precision across the full operating temperature range from 21°C to 300°C.
Solution Approach 2:
The patent uses permanent magnets made from high-temperature resistant composite materials that maintain their magnetic properties at elevated temperatures. These specialized magnetic materials resist demagnetization and flux density loss, enabling reliable position detection even when operating at temperatures up to 300°C where conventional magnets would fail.
4Measurement precision
If complex electronic systems are used for sensor operation, then measurement capability is improved, but reliability decreases due to component failure risk in harsh environments
Solution Approach 1:
The patent replaces fragile, expensive electronic components with simple, robust permanent magnets and reed switches that have no moving parts and high resistance to failure. These components are designed to be replaceable if needed but are engineered to last the full service life in harsh downhole environments, significantly improving reliability while maintaining measurement precision.
Solution Approach 2:
The patent substitutes electronic sensor systems with a mechanically simple magnetic field detection system using permanent magnets and reed switches. This elimination of complex electronics removes the primary source of component failures in harsh environments while preserving accurate position measurement capability, thereby dramatically improving overall system reliability.
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 offers precise positioning and movement measurement with improved reliability and reduced complexity, allowing operation in extreme temperatures and minimizing component failure risks, while reducing manufacturing costs and space requirements.
Implementation Method 1
a magnetic sensor array with Reed switches and a PCB-less design, actuated by a magnetic field
Implementation Method 2
at least one conductor member having a plurality of contact regions spaced apart at first intervals of at least a first length along a longitudinal axis of said at least one conductor member
Data Source
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AI summary
A magnetic sensor array is presented for a well apparatus for determining the position of at least one movable component with respect to a fixed component of a downhole tool. The array comprises at least one conductor member having a plurality of contact regions spaced apart at first intervals of at least a first length along a longitudinal axis of said at least one conductor member and a plurality of magnetic sensors, each one of which is operably coupled to one of said plurality of contact regions and actuatable by a magnetic field from a magnetic actuator.