Rod Pumping System Torque Feedback Fillage Control
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Solution Overview
Problem
Sucker rod pumping systems face challenges in accurately determining wellbore fluid levels and adjusting pumping speed to avoid 'pump-off' conditions, leading to inefficient operation and potential damage to equipment.
Innovation Solution
Monitoring the torque of the prime mover and processing it using a microprocessor with an algorithm to create a filtered torque array, which determines pump fillage and adjusts the prime mover speed for optimal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pumping speed is increased to maximize oil extraction, then productivity improves, but the risk of pump-off conditions and equipment damage increases
Solution Approach 1:
The system continuously monitors torque values during pump strokes and uses this feedback to calculate pump fillage. The controller adjusts pump speed based on real-time fillage data, creating a closed-loop control system that prevents pump-off conditions while maximizing extraction efficiency.
Solution Approach 2:
The pump speed is made variable rather than fixed. The controller dynamically adjusts the pump stroke speed based on real-time torque measurements and calculated fillage, allowing the system to adapt to changing reservoir conditions and maintain optimal operation without causing equipment damage.
2Reliability
If the pump stroke speed is reduced to prevent pump-off conditions, then equipment reliability improves, but productivity decreases
Solution Approach 1:
The system dynamically adjusts pump speed based on real-time torque monitoring and fillage calculation. When fillage is high, the controller reduces speed to prevent pump-off conditions. When fillage is low, the controller increases speed to maximize extraction, optimizing the balance between reliability and productivity.
Solution Approach 2:
The pump operating parameters (speed, stroke length) are changed based on calculated fillage values. The controller modifies these parameters to match actual reservoir conditions, allowing the system to operate at optimal speed when fillage is low and reduce speed when fillage is high, thereby preventing pump-off conditions without unnecessarily reducing productivity.
3Measurement precision
If torque monitoring and speed adjustment systems are added, then pump fillage determination accuracy improves, but device complexity increases
Solution Approach 1:
The system replaces complex mechanical measurement devices with electronic torque sensors and microprocessor-based calculation. Instead of using complex mechanical linkages to directly measure fillage, the system uses torque monitoring combined with mathematical algorithms to calculate fillage, simplifying the overall system while improving measurement accuracy.
Solution Approach 2:
Torque values serve as an intermediary parameter that indirectly indicates pump fillage. Rather than directly measuring fillage with complex sensors, the system uses torque monitoring as a proxy, processing this intermediate data through algorithms to determine fillage, thereby simplifying the measurement system while maintaining accuracy.
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 allows for accurate determination of pump fillage and adjustment of pumping speed, preventing pump-off conditions and reducing the risk of equipment damage, thereby ensuring cost-effective and efficient operation of the sucker rod pumping system.
Implementation Method 1
monitoring the torque of the prime mover providing motive force to the pump system
Implementation Method 2
The downward stroke starts at the highest point of the horsehead and continues until the horsehead has reached its lowest point. During the down stroke the rod string and piston in the downhole reciprocating pump descend as gravity pulls them downward.
Data Source
AI summary
A method and system for determining the pump fillage of a sucker rod pumping system using torque feedback when pumping wellbore fluids from the particular well on which the sucker rod pumping system is installed. During the pump stroke, a microprocessor samples torque of the pump's mechanical system at an associated horsehead position at regular intervals and once the stroke is completed the raw torque samples and associated horsehead positions are placed in an array, the array of raw torque samples and horsehead positions can be filtered by the microprocessor into a second filtered array and then converted by the microprocessor into a rotatum array (derivative of torque with respect to time) of one or both of the raw or filtered arrays and stored as a rotatum array. The down stroke portion of the rotatum array is then analyzed by the microprocessor to determine the horsehead position when the piston of the down hole pump encounters wellbore fluid in the well (pump fillage). The microprocessor, based on the determined pump fillage, adjusts the speed of the pumping system to maintain an optimal pump fillage determined to be the most economical for the particular well on which the sucker rod pumping system is installed.