Wellbore Pressure Estimation Using Acoustic Flow Inference
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Solution Overview
Problem
The challenge in the oil and gas industry is the limited availability and reliability of downhole pressure sensors and flow meters due to cost constraints and equipment degradation, leading to unreliable downhole information.
Innovation Solution
A method and system that utilize temperature and acoustic sensors to estimate downhole pressure and flow rates by iteratively adjusting estimated pressures until the calculated total mass flow rate matches a known value within a threshold, using average temperature and speed of sound in multiphase fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple downhole pressure sensors and flow meters are deployed, then measurement precision and reliability improve, but device complexity and cost increase
Solution Approach 1:
The patent uses acoustic wave propagation as a virtual copy or surrogate for direct pressure measurement. By measuring the speed of sound in the fluid, the system infers pressure conditions without requiring physical pressure sensors at multiple downhole locations. This acoustic copying approach replaces multiple expensive pressure sensors with a single acoustic sensor system.
Solution Approach 2:
The patent replaces mechanical pressure sensors and flow meters with an acoustic-based measurement system. Instead of using mechanical devices that physically contact the wellbore environment, the system uses acoustic wave propagation through the fluid to derive pressure and flow rate information, thereby eliminating the need for multiple mechanical sensing devices.
2Reliability
If multiple downhole pressure sensors and flow meters are deployed, then reliability improves, but cost increases
Solution Approach 1:
The acoustic wave propagation method creates a virtual measurement system that copies the information-gathering function of multiple expensive pressure sensors and flow meters. By using acoustic velocity measurements combined with thermodynamic models, the system replicates the reliability of multiple sensors without the associated cost, providing robust downhole pressure and flow rate estimation through physics-based inference.
Solution Approach 2:
The patent employs acoustic sensors that are significantly cheaper than downhole pressure sensors and flow meters. The acoustic sensing approach uses inexpensive surface or near-surface equipment to measure sound wave propagation, replacing expensive, fragile downhole instrumentation with cost-effective acoustic measurement technology.
3Measurement precision
If downhole tools are used to obtain downhole information, then measurement precision improves, but device complexity and placement challenges increase
Solution Approach 1:
The patent replaces the need for physical downhole tool deployment with acoustic wave propagation measurements. Instead of lowering pressure sensors and flow meters into the wellbore through complex deployment operations, the system uses acoustic sensors that can measure pressure and flow rate information through the fluid column without direct downhole instrument placement, dramatically simplifying the operational complexity.
Solution Approach 2:
The patent introduces acoustic waves as an intermediary medium to transfer information from the downhole environment to surface measurement equipment. The acoustic waves propagate through the fluid, carrying pressure and flow rate information from difficult-to-reach downhole locations to easily accessible surface sensors, thereby eliminating the need for complex downhole tool placement while maintaining measurement precision.
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
Enables accurate estimation of downhole pressure and flow rates without the need for multiple sensors, providing reliable information for wellbore management and production optimization.
Implementation Method 1
obtaining an average temperature of a multiphase fluid and an average speed of sound in the multiphase fluid in a section of the wellbore
Implementation Method 2
obtaining an average temperature of a multiphase fluid and an average speed of sound in the multiphase fluid
Data Source
AI summary
A method of determining wellbore pressures and multiphase fluid flow rates includes obtaining an average temperature and an average speed of sound in a section of the wellbore. The method further includes calculating phase mass flow rates of the multiphase fluid through the section at least based on the average temperature, the average speed of sound, an estimated pressure at an estimated-pressure location in the wellbore, and a difference between a known pressure and the estimated pressure. The method also includes calculating a total mass flow rate of the multiphase fluid through the section based on the phase mass flow rates of the multiphase fluid. The phase mass flow rates and the total mass flow rate of the multiphase fluid are calculated iteratively by adjusting the estimated pressure until the total mass flow rate is within a threshold value of a known total mass flow rate of the multiphase fluid.