Acoustic Piston Positioning in Downhole Displacement Pumps
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Solution Overview
Problem
Conventional systems for determining piston position in modular dynamics testers used in downhole operations lack accuracy, leading to pressure surges and improper pump speeds due to inadequate positioning techniques.
Innovation Solution
An acoustic method using a transducer to emit and receive tone bursts, calculating the time of flight to determine piston position within the cylinder, allowing for precise positioning and improved pump control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional Hall effect transducers are used to determine piston position, then the positioning system is simple in structure, but the measurement precision is insufficient leading to inaccurate piston position determination
Solution Approach 1:
The patent replaces the conventional Hall effect transducer (electromagnetic sensing) with an acoustic transducer system that uses sound wave propagation and reflection principles. The acoustic transducer emits tone bursts into the hydraulic fluid, and the reflected echoes from the piston surface are detected and processed to calculate piston position, thereby improving measurement precision while maintaining system simplicity
Solution Approach 2:
The patent introduces acoustic waves as an intermediary medium to determine piston position. The tone bursts travel through the hydraulic fluid as a carrier wave, reflecting off the piston surface and carrying position information back to the receiver, enabling accurate non-contact measurement without complex mechanical or electromagnetic transducers
2Reliability
If piston position is not accurately determined, then the system operation is simple, but pressure surges occur when the piston meets the cylinder end
Solution Approach 1:
The patent implements a feedback control system where the acoustic transducer continuously monitors piston position by emitting tone bursts and analyzing the reflected echoes. The calculated piston position is fed back to the pump speed controller, which adjusts the pump speed in real-time to reduce or eliminate pressure surges when the piston approaches the cylinder end, thereby improving system reliability
Solution Approach 2:
The patent uses preliminary action by continuously tracking piston position through acoustic measurements before the piston reaches the cylinder end. The system calculates the time of flight of the tone bursts and determines piston position in advance, allowing the control system to prepare and adjust pump speed proactively to prevent pressure surges before they occur
3Productivity
If conventional positioning methods are used, then the pump speed control is simple, but the pump speed control is improper leading to operational inefficiency
Solution Approach 1:
The patent implements feedback control where the acoustic transducer system continuously provides piston position information to the pump speed controller. The controller uses this feedback to dynamically adjust pump speed based on actual piston position, ensuring optimal operation and improving productivity while the added complexity is managed through integrated electronics
4Measurement precision
If acoustic transducer tone bursts are used to determine piston position, then the measurement precision is improved, but the use of energy increases due to continuous tone burst emission
Solution Approach 1:
The patent uses periodic action by emitting acoustic tone bursts at specific intervals rather than continuously. The transducer emits tone bursts periodically, listens for echoes during the intervals, and calculates piston position based on the time of flight measurements, thereby reducing energy consumption while maintaining accurate continuous monitoring capability
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 method provides accurate piston position determination, reducing pressure surges and enabling better control of pump speeds, and allows for more accurate estimation of fluid flow rates, thereby enhancing the efficiency of downhole operations.
Implementation Method 1
providing a transducer tone burst to provide acoustic energy toward the piston
Implementation Method 2
reflecting the transducer tone burst by a surface of the piston
Implementation Method 3
calculating time of flight for the transducer tone burst, determining the piston position in the downhole tool based upon the calculated time of flight of the transducer tone burst
Data Source
AI summary
A method for determining a piston position in a downhole tool, having steps of providing a transducer in the downhole tool, wherein the tool has a piston used to create a vacuum for the downhole tool, providing a transducer tone burst to provide acoustic energy toward the piston, reflecting the transducer tone burst by a surface of the piston, receiving the transducer tone burst at a receiver, calculating time of flight for the transducer tone burst and determining the piston position in the downhole tool based upon the calculated time of flight of the transducer tone burst.