Multiphase Fluid Sensor Probe Using Optical and Electrical Sensing

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Solution Overview

Problem

Existing downhole sensors cannot distinguish between liquid hydrocarbons, water, and gas in multiphase fluids and often cannot withstand the harsh conditions of the downhole environment during oil and gas well drilling operations.

Innovation Solution

A hybrid optical and electrical sensor probe with an optically transparent cylindrical member and metal electrodes is used, capable of differentiating between phases based on refractive index and electrical conductivity, and designed to withstand temperature and pressure variations, using a shaped tip and a protective coating to prevent fluid infiltration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing sensors are used for downhole multiphase fluid measurement, then the device complexity is reduced, but the measurement precision deteriorates because they cannot distinguish between liquid hydrocarbons, water, and gas

Engineering Contradiction:
Improvephase differentiation capabilityVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines optical sensing (refractive index measurement) and electrical sensing (conductivity measurement) into a single integrated sensor assembly. The optical sensor uses a prism or fiber optic element to detect refractive index changes, while electrical electrodes measure conductivity. By merging these two independent sensing mechanisms into one device, the patent achieves the capability to distinguish between liquid hydrocarbons, water, and gas phases simultaneously, resolving the technical contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor employs composite material structures, including optically transparent materials with specific refractive indices for the optical sensing element, and protective coatings that are permeable to certain phases while blocking others. The combination of different materials (optical materials, conductive materials, protective coatings) within a single sensor enables multifunctional measurement capabilities without requiring multiple separate devices.

Inventive Principle:
Principle #40Composite materials

2Reliability

If simple sensor structures are used, then the ease of manufacture is improved, but the reliability deteriorates because they cannot withstand the rigors of the downhole environment

Engineering Contradiction:
Improvedownhole environment resistanceVSAvoidsensor manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent incorporates protective coatings and sealed enclosures around the optical and electrical sensing elements before deployment into the downhole environment. These protective structures are designed in advance to withstand high temperatures, pressures, and corrosive conditions. The optical prism or fiber optic element is encapsulated in a protective housing that maintains optical properties while providing environmental protection, and electrical components are sealed to prevent fluid infiltration, thereby ensuring reliability without requiring complex post-manufacturing modifications.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The sensor utilizes thin-film protective coatings that are applied to the optical and electrical components. These thin films provide environmental protection while maintaining the functional properties of the underlying materials. The flexible yet protective nature of these coatings allows the sensor to withstand downhole conditions without requiring bulky protective structures, balancing reliability with manufacturability.

Inventive Principle:
Principle #30Flexible shells and thin films

3Measurement precision

If optical and electrical sensors are combined in a single probe, then the measurement precision is improved for multiphase differentiation, but the device complexity increases

Engineering Contradiction:
Improvefluid composition analysis accuracyVSAvoidintegrated sensor probe complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent designs a universal sensor probe that performs multiple measurement functions simultaneously. The optical sensing element detects refractive index variations to identify different fluid phases, while electrical electrodes measure conductivity to further differentiate between phases. Both sensing mechanisms share common structural elements such as the protective enclosure, mounting structure, and signal processing electronics. This multi-functional design enables precise fluid composition analysis while reducing overall device complexity compared to using separate optical and electrical sensors.

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

Solution Approach 2:

The sensor structure employs a nested configuration where the optical sensing element and electrical electrodes are integrated within a common protective housing. The optical prism or fiber optic is positioned centrally, with electrical electrodes arranged around it, all contained within a single sealed enclosure. This nested arrangement minimizes the overall probe size and reduces the number of external components, thereby reducing device complexity while maintaining the precision benefits of combined optical and electrical measurement capabilities.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 sensor effectively distinguishes between water, oil, and gas phases in multiphase fluids, providing accurate measurements and withstanding the rigors of the downhole environment, enabling precise fluid composition analysis.

Implementation Method 1

an optical sensor having a shaped tip and operable to detect an optical refractive index of the multiphase fluid

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

an electrical sensor operable to measure an electrical conductivity of the multiphase fluid

Methodology Applied
Scientific EffectElectrical Conductivity: Conduction (electrical)

Data Source

PatentEP2947265B1Optical and electrical sensing of a multiphase fluid
Publication Date: 2024.03.13 SERVICES PETROLIERS SCHLUMBERGER SA
  • EP2947265B1 patent drawingFigure 1
  • EP2947265B1 patent drawingFigure 2~5
  • EP2947265B1 patent drawingFigure 6~8

AI summary

Apparatus and methods for optical and electrical sensing different phases of a multiphase fluid. The apparatus includes a cylindrical member (210) formed with an optically transparent material including a first end with a shaped tip (215) and a second end operable to receive an optical conductor (275). The apparatus also includes first and second electrodes (225, 230) disposed on the cylindrical member operable to receive first and second electrical conductors (260, 265), respectively.