Pumpjack Linear Alternator for Local Power and Position Sensing
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Solution Overview
Problem
The existing methods for powering devices and instruments at oil and gas wells are inefficient due to the need for long and costly power cables, which are prone to damage and maintenance issues, and battery-operated devices require frequent recharging or replacement.
Innovation Solution
A linear alternator is mounted on the pump at the well site to generate power using the up-and-down motion of the pump, converting mechanical work into electrical energy to supply power to devices and instruments, with optional position sensors to measure the pump's vertical position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power cables are run from the motor drive to each device, then power can be supplied to devices and instruments, but the well site becomes cluttered and the cables are susceptible to wear and tear and damage
Solution Approach 1:
The patent extracts the power generation function from the distant motor drive and places it directly at the well site where devices need power. The linear alternator is mounted on the pump assembly, eliminating the need for long power cables running across the well site by generating power locally at the source.
Solution Approach 2:
The pump assembly serves dual purposes: it both pumps wellbore fluids and generates electrical power through the mounted linear alternator. The mechanical energy already present in the pumping motion is converted to electrical energy, allowing the system to power its own monitoring devices without external power sources or lengthy cable runs.
2Adaptability or versatility
If extremely long cables are used for devices located downhole, then power can reach distant devices, but installation and maintenance costs increase
Solution Approach 1:
The patent removes the need for extremely long power cables by extracting power generation capability and placing it directly on the pump assembly. This eliminates the requirement for costly long-distance cable installation and maintenance while still providing power to all necessary devices at the well site.
Solution Approach 2:
The linear alternator acts as an intermediary device that converts the mechanical motion of the pump into electrical energy right at the well site. This intermediary power generation solution replaces the need for long cable runs, providing a more cost-effective means of powering downhole and surface devices.
3Ease of operation
If battery-operated devices are used, then devices can operate without power cables, but the batteries need to be regularly recharged or replaced
Solution Approach 1:
Instead of using finite battery power that requires periodic replacement, the system implements self-sustaining power generation. The linear alternator continuously converts the pump's mechanical motion into electrical energy, providing indefinite operation without the need for battery recharging or replacement.
Solution Approach 2:
The patent changes the energy supply parameter from finite battery storage to continuous mechanical-to-electrical energy conversion. By mounting the linear alternator on the pump assembly, the system transforms the limited-duration battery operation into indefinite power supply based on the ongoing pumping operation.
4Object-generated harmful factors
If the motor drive is located away from the devices, then the motor drive can be positioned for optimal operation, but power cables need to be run which clutter the well site
Solution Approach 1:
The patent extracts the power generation function from the motor drive location and places it directly on the pump assembly at the well site. This eliminates the need for power cables running across the well site while maintaining optimal positioning of both the motor drive and the power generation components.
Solution Approach 2:
The pump assembly becomes a multi-functional unit, serving both as the fluid pumping mechanism and as the power generation source. By mounting the linear alternator on the pump, the system combines two functions (pumping and power generation) into one location, eliminating cable clutter while maintaining operational efficiency.
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 solution eliminates the need for long power cables, reduces maintenance costs, and provides a reliable power source for monitoring and controlling the pump's operational parameters, enhancing the efficiency and cost-effectiveness of oil and gas production.
Implementation Method 1
The linear alternator uses the up-and-down motion of the pump to drive a linear rotor back and forth in a linear stator to generate power
Data Source
AI summary
Systems and methods for providing power to devices at a well site employ a linear alternator to generate power at a well site. The linear alternator is mounted on a pump at the well site and uses the up-and-down motion of the pump to generate power. The pump may be a nodding donkey head pump or other sucker rod pump mechanisms that operate based on linear vertical motion. The linear vertical motion drives a linear rotor back and forth through a linear stator to induce current in the linear alternator. This allows the linear alternator to convert a portion of the mechanical work performed by the pump into electrical energy that can be supplied to the devices. In some embodiments, the pump-mounted linear alternator can be equipped with a position sensor to directly measure a vertical position of the pump as the alternator travels up and down with the pump.