Ultrasonic and Capacitance Sensors for Annular Flow Measurement
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Solution Overview
Problem
Current production logging techniques face challenges in accurately measuring the flow rate of a liquid annulus layer on the casing wall in downhole environments, particularly in annular flow regimes, due to sensor damage concerns and limitations in non-contact measurement methods for thin liquid layers.
Innovation Solution
A production logging tool equipped with a combination of non-contact ultrasonic and electrical capacitance sensors is used to measure the properties of the liquid annulus layer without direct contact, allowing for precise determination of flow rate, liquid type, and water-in-liquid ratio, while maintaining sensor safety by maintaining a controlled distance from the casing wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If contact sensors are used to measure liquid annulus flow rate, then measurement accuracy is improved, but sensor damage risk increases due to proximity to casing wall
Solution Approach 1:
The patent replaces mechanical contact sensors with non-contact measurement techniques, specifically electromagnetic sensors that measure liquid flow through the casing wall without physical contact. This substitution eliminates the mechanical wear and damage risks associated with contact sensors while maintaining measurement capability through electromagnetic field interaction with the liquid annulus.
Solution Approach 2:
The patent introduces an electromagnetic field as an intermediary between the measurement system and the liquid annulus. The sensors placed inside the casing use electromagnetic fields to detect liquid flow characteristics through the casing wall, acting as a mediator that transfers measurement information without requiring direct physical contact between the sensor and the liquid.
2Reliability
If non-contact sensors are used to avoid damage, then sensor reliability is improved, but measurement precision deteriorates for thin liquid layers
Solution Approach 1:
The patent employs electromagnetic sensors that operate by detecting changes in electromagnetic field parameters (such as impedance, capacitance, or inductance) caused by the presence and movement of the liquid annulus. By measuring these parameter changes rather than relying on geometric proximity, the system achieves high measurement precision for thin liquid layers while maintaining sensor safety through non-contact operation.
3Device complexity
If standard flow measurement techniques are used, then device simplicity is maintained, but adaptability to annular flow regime deteriorates
Solution Approach 1:
The patent employs electromagnetic sensors that serve multiple measurement functions within a single device configuration. These sensors can measure liquid annulus thickness, flow rate, and other liquid characteristics simultaneously, providing adaptability to the annular flow regime without requiring complex specialized equipment for each measurement type.
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 tool provides accurate and precise measurements of the liquid annulus flow rate and type, enabling effective management of hydrocarbon production by overcoming the limitations of existing methods in annular flow regimes without damaging the sensors.
Implementation Method 1
an ultrasonic sensor adapted to transmit towards the liquid annulus layer a pulse to define a reflected pulse
Implementation Method 2
The pulses encode fluid flow velocity as a result of the Doppler shift
Implementation Method 3
electrical capacitance sensors is used to measure the properties of the liquid annulus layer
Data Source
AI summary
Provided is a tool-body that arranges ultrasonic and electrical capacitance sensors at close distances to the casing wall of the wellbore such that properties of thickness, flow velocity, acoustic impedance and the dielectric constant of the liquid layer are measured at a number of circumferential locations inside the casing of the wellbore. These measured values may then be combined to derive the average flow rate of the layer and also used to identify whether the liquid is water or condensate/oil, or a mixture of the two with a certain water-in-liquid ratio. Combined with a gas flow rate and a liquid droplets concentration measurement, the total liquid flow rate and liquid type can be derived.