Wellbore Flowrate Determination via Thermal Relaxation
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Solution Overview
Problem
Existing methods for determining fluid flowrates in wellbores, particularly in horizontal and multiple producing zones, are limited by the need for distributed temperature profiles and permanent sensor installations, making them unsuitable for adaptable and easy installation in various downhole locations.
Innovation Solution
A method involving a temperature sensor and a temperature sink, such as a heat or cold sink, is used to perturb and monitor the temperature transition at specific locations within the wellbore, allowing for localized flowrate determination by correlating the temperature relaxation half-life with fluid flowrate, which can be applied temporarily or permanently and is adaptable to different wellbore configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If distributed temperature sensors and distributed temperature profiles are used to determine flowrate, then measurement precision is improved, but device complexity and installation difficulty increase
Solution Approach 1:
The patent extracts the temperature sensing function from a distributed array of sensors and concentrates it into a single temperature sensor. This single sensor is positioned to measure temperature at a specific location where fluid flows, eliminating the need for multiple distributed sensors while maintaining flowrate determination capability through localized temperature measurement and perturbation analysis
Solution Approach 2:
The patent introduces a temperature sink as an intermediary element that creates a controlled temperature perturbation in the fluid. This temperature sink acts as a mediator between the single temperature sensor and the flowing fluid, enabling the sensor to detect temperature changes that correlate with flowrate without requiring the sensor to be directly in the flow path or part of a distributed array
2Reliability
If permanent sensor installations are used in wellbores, then measurement reliability is improved, but ease of operation and adaptability decrease
Solution Approach 1:
The patent transitions from static, permanent sensor installations to a dynamic system where the temperature sink and single temperature sensor can be temporarily positioned, deployed, and removed as needed. This dynamic approach allows the same measurement system to be adapted to different wellbore locations and configurations without permanent modification, improving ease of operation while maintaining measurement reliability through controlled temperature perturbation and monitoring
3Measurement precision
If distributed temperature profiles along wellbore length are acquired, then flowrate measurement capability is improved, but loss of time and measurement complexity increase
Solution Approach 1:
The patent applies preliminary action by using the temperature sink to create a controlled temperature perturbation before the fluid reaches the measurement location. This pre-applied temperature change allows the single temperature sensor to detect flowrate-related temperature variations at a specific point in time, eliminating the need to acquire and analyze temperature profiles over extended periods or along the entire wellbore length
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 approach enables accurate and efficient flowrate determination in wellbores, reducing the complexity of installation and measurement, and is applicable to both horizontal and vertical sections, providing real-time or near-real-time data for improved hydrocarbon production management.
Implementation Method 1
measuring an equilibrium temperature of a location of interest within or proximate to the passage
Implementation Method 2
The temperature of the location of interest is perturbed to a second temperature
Implementation Method 3
the temperature of the location of interest is then allowed to return to its equilibrium temperature. The temperature of the location of interest is monitored as it transitions between the second temperature and the equilibrium temperature
Implementation Method 4
The use of a fiber optic cable equipped with a temperature sensor
Data Source
AI summary
A method and apparatus are useful for determining the flowrate of fluid flowing within a passage. The method comprises the step of measuring the equilibrium temperature of a location of interest within or proximate to the passage within which fluid flows. The temperature of the location of interest is perturbed to a second temperature, and the temperature of the location of interest is then allowed to return to its equilibrium temperature. The temperature of the location of interest is monitored as it transitions between the second temperature and the equilibrium temperature. The monitored temperature transition is then used to determine the flowrate of the fluid flowing within the passage.