Downhole Valve Sleeve Sensing With Circumferential Error Correction

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Solution Overview

Problem

Existing downhole sliding sleeve valve assemblies face challenges in accurately determining the relative position of the sleeve and housing due to misalignment, bending, and other structural deviations, which can lead to errors in valve operation.

Innovation Solution

The use of circumferentially spaced inductive proximity sensors that process signals from markers on the sleeve and housing to provide position information, correcting for errors by integrating or subtracting signals from primary and reference sensors, allowing for precise alignment and operation of the valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single sensor is used to detect sleeve position, then the device complexity is reduced, but the measurement precision deteriorates due to misalignment and structural deviations

Engineering Contradiction:
Improvesensor assembly complexityVSAvoidposition detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The sensor assembly is segmented into multiple circumferentially spaced sensors (at least two) that independently detect position information. Each sensor provides measurements from different angular positions, allowing the system to detect and correct for misalignment and structural deviations through signal processing of multiple independent measurements rather than relying on a single sensor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from single-point measurement to multi-point circumferential measurement by spacing sensors around the sleeve. This adds a circumferential dimension to the position detection, enabling the system to identify and compensate for angular misalignment and bending errors that would be invisible to a single sensor.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple circumferentially spaced sensors are used to correct alignment errors, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improveposition detection accuracyVSAvoidsensor assembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The multiple sensors serve multiple functions simultaneously: they detect the absolute position of the sleeve, identify angular misalignment between housing and sleeve, detect bending or bowing of the assembly, and provide redundant measurements for error correction. This multi-functionality justifies the increased complexity by delivering comprehensive diagnostic and measurement capabilities from a single sensor array.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution enables accurate determination of the sleeve's position relative to the housing, reducing errors from misalignment and structural deviations, ensuring reliable operation of the downhole valve assembly.

Implementation Method 1

the first and second primary sensors comprise inductive proximity sensors

Methodology Applied
Scientific EffectInductive proximity sensing: Electromagnetic Induction

Data Source

PatentEP3612708B1Downhole valve assembly
Publication Date: 2021.03.17 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP3612708B1 patent drawingFigure 1
  • EP3612708B1 patent drawingFigure 2~3
  • EP3612708B1 patent drawingFigure 4~5

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.