Optical Mini-Spinner Flowmeter for Downhole Fluid Measurement

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Solution Overview

Problem

Conventional flowmeters in hydrocarbon wells face issues with magnetic detection systems being affected by metallic debris, leading to unbalanced rotating parts and unreliable measurements, and optical flow meters have low reliability and cannot measure fluid direction effectively.

Innovation Solution

A mini-spinner flowmeter using an impeller with axially extending vanes and an optical section comprising emitting and receiving optical fibers to measure fluid linear velocity and direction, with no magnetic components to avoid debris interference and provide accurate direction measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic detection is used to measure fluid velocity, then velocity measurement capability is provided, but metallic debris is attracted by the magnetic field causing unbalanced rotating parts and measurement perturbation

Engineering Contradiction:

Improvefluid velocity measurementVSAvoidsensor operation reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the magnetic detection system with an optical detection system. Instead of using a magnet and magnetic flux sensor, the invention uses an optical fiber to detect light reflected from the impeller vanes. This substitution eliminates the magnetic field that attracts metallic debris, thereby resolving the contradiction between measurement capability and reliability in environments with metallic dust and debris.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If conventional optical flow meter is used, then fluid velocity measurement is enabled, but the reliability is low and fluid direction measurement is not possible

Engineering Contradiction:

Improvefluid velocity measurementVSAvoidflow meter reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent enhances the optical detection system by using multiple optical fibers positioned at different angular positions around the impeller. This spatial arrangement in multiple dimensions enables not only velocity measurement through light reflection detection but also direction measurement by analyzing which optical fibers receive reflected light and the timing characteristics. This resolves the limitation of conventional optical flow meters that cannot measure fluid direction.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If miniaturized sensor is deployed for local measurements, then deployment flexibility is improved, but sensor robustness in harsh environment must be maintained

Engineering Contradiction:

Improvedeployment flexibilityVSAvoidsensor performance in harsh environment

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent employs an optical fiber as the detection element, which inherently possesses flexibility and can be miniaturized. The optical fiber is positioned close to the impeller vanes and can withstand harsh downhole conditions including high temperature (up to 200°C), high pressure (up to 2000 bars), and corrosive fluids. The optical fiber's flexibility enables miniaturization and adaptable deployment in various downhole configurations while maintaining robustness through its resistance to environmental degradation.

Inventive Principle:

Principle #30Flexible shells and thin films

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 optical mini-spinner flowmeter operates effectively in harsh environments, maintaining metrology performance, avoiding magnetic debris interference, and enabling accurate fluid direction measurement, while being miniaturized for local deployment in hydrocarbon wells.

Implementation Method 1

an emitting optical fiber, positioned such as to face a vane rotation trajectory

Methodology Applied

Scientific EffectOptical fiber transmission: Optical Fibre

Implementation Method 2

the vanes are reflective such that, in use, a light energy emitted by the emitting optical fiber and reflected backward by anyone of the vanes is received by the first receiving optical fiber and/or the second receiving optical fiber

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS11131570B2Mini-spinner flowmeter and downhole tool comprising an array of mini-spinner flowmeters for operation in hydrocarbon well

Publication Date: 2021.09.28 OPENFIELD SAS

AI summary

A mini-spinner flowmeter measures a fluid linear velocity and/or a fluid direction of a fluid present in a hydrocarbon well. It comprises an impeller formed with a plurality of axially extending vanes longitudinally secured to a shaft, the shaft extending along a longitudinal axis, the impeller being caused to rotate at an impeller angular velocity depending on the fluid linear velocity and in a rotational direction depending on the fluid direction; and a support having a bearing positioned on each end of the shaft and a through-hole securing an optical section. The vanes are reflective such that, in use, a light energy emitted by an emitting optical fiber and reflected backward by anyone of the vanes is received by a first receiving optical fiber and/or a second receiving optical fiber, the reflected light energy containing information indicative of the fluid linear velocity and/or the fluid direction.