Linear Pump Motor Rotary-to-Linear Mechanism
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Solution Overview
Problem
Linear pump and motor systems face issues such as rod stretch, gas lock, and overheating due to pressure differentials and gas buildup, which affect reliability and efficiency, especially in low production wells.
Innovation Solution
A pressure compensation device (PCD) and gas mitigation assembly are integrated with a rotary-to-linear mechanism, where the PCD minimizes pressure differentials between lubrication and external fluids, and the gas mitigation assembly mechanically opens valves to release trapped gas, enhancing operational reliability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a linear pump and motor system operates in low production wells, then productivity is improved, but the system overheats due to insufficient fluid flow
Solution Approach 1:
The system separates the motor cooling function from the production fluid flow by introducing a dedicated lubrication fluid circulation system. The motor is provided with lubrication fluid that circulates through bearings and gears independently of production fluid, allowing the motor to be cooled and lubricated effectively even when production fluid flow is insufficient for low production wells.
2Reliability
If pressure differential between lubrication fluid and external fluid is large, then motor sealing is improved, but the system experiences gas lock and reduced reliability
Solution Approach 1:
A pressure compensation device is introduced as an intermediary mechanism between the lubrication fluid chamber and the external fluid chamber. This device includes a piston that moves in response to pressure differential to adjust the volume of the lubrication fluid chamber, thereby compensating for pressure differences and preventing gas lock while maintaining effective sealing.
Solution Approach 2:
The lubrication fluid chamber volume is made dynamically adjustable through the pressure compensation device. The piston within the pressure compensation device moves automatically in response to pressure differential changes, dynamically adjusting the chamber volume to maintain pressure balance and prevent gas accumulation that would cause gas lock.
3Productivity
If rod pump systems are used to pump fluids, then productivity is improved, but rod stretch and gas lock occur reducing reliability
Solution Approach 1:
The traditional rod pump mechanical system is replaced with a linear pump and motor system that eliminates the rod string entirely. The linear motor directly drives the pumping action through a rotary-to-linear mechanism, removing the mechanical components (rods, polished rods, etc.) that are susceptible to stretch, fatigue, and gas lock, thereby significantly improving system reliability while maintaining productivity.
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
The solution provides precise and repeatable control of stroke length, prevents lubricating oil mixing with external fluids, and allows operation in low production wells without overheating, reducing the need for significant fluid flow and horsepower, thus improving system reliability and efficiency.
Implementation Method 1
The piston may move within the tubular in response to a pressure differential between a first and second fluid
Data Source
AI summary
A linear pump and motor system includes a motor, rotary-to-linear mechanism, pressure compensation device (PCD), and gas mitigation assembly. The rotary-to-linear mechanism may translate rotation of a motor into linear motion to provide a pumping action. A PCD may minimize a pressure differential between lubrication fluids and external fluids. A gas mitigation assembly may provide a mechanism that mechanically opens a valve. In some embodiments, a PCD may be utilized separately from the linear pump. In some embodiments, a gas mitigation assembly may be utilized separately from the linear pump.