Magnetic Coupling for Downhole Pump Sealing
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Solution Overview
Problem
Surface driven downhole pump systems require regular maintenance and are unreliable in high wellhead pressure and H2S environments due to the risk of stuffing box leakage, posing safety and environmental concerns.
Innovation Solution
A surface driven downhole pump system utilizing a magnetically transparent enclosure with a magnetic driver and follower, allowing for magnetic coupling across a gap to transfer power without the need for traditional stuffing boxes, ensuring zero leakage and reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stuffing boxes with packing elements are used to seal around rods, then well fluids can be contained, but regular maintenance and inspection are required to prevent leakage
Solution Approach 1:
The patent replaces the mechanical stuffing box sealing system with a magnetic coupling system. The magnetic driver and magnetic follower are separated by a magnetically transparent barrier that prevents fluid leakage while allowing magnetic field transmission. This eliminates the need for packing elements that require maintenance, as the magnetic coupling provides continuous sealing without mechanical contact between the rod and wellhead environment.
Solution Approach 2:
The patent introduces a magnetically transparent barrier as an intermediary between the driver and follower sides. This barrier allows magnetic field penetration for power transmission while providing complete fluid isolation. The barrier acts as a mediator that enables both functions: it transmits the magnetic coupling force while simultaneously preventing any fluid leakage, thereby eliminating the maintenance issues associated with traditional stuffing boxes.
2Power
If stuffing boxes are used in high wellhead pressure and high H2S concentration environments, then power can be transmitted to downhole pump, but leakage risk increases posing safety and environmental concerns
Solution Approach 1:
The patent replaces the mechanical stuffing box system with a magnetic coupling system that uses a magnetically transparent barrier. This barrier provides complete fluid isolation between the high-pressure wellhead environment and the driver side, eliminating leakage pathways. The magnetic field penetrates the barrier to transmit power without requiring any openings or mechanical seals that could leak, thereby completely preventing H2S and hydrocarbon leakage risks.
Solution Approach 2:
The magnetically transparent barrier serves as an intermediary that enables power transmission while blocking harmful fluid leakage. The barrier is designed to be transparent to magnetic fields, allowing the magnetic driver to couple with the magnetic follower across the barrier. Simultaneously, the barrier provides complete fluid isolation, preventing any leakage of high-pressure well fluids containing H2S, thus eliminating safety and environmental concerns.
3Reliability
If traditional stuffing box systems are used, then rod movement can be sealed, but the system requires regular maintenance such as packing element replacement and grease injection
Solution Approach 1:
The patent replaces the mechanical stuffing box with a magnetic coupling system using a magnetically transparent barrier. The magnetic driver and follower are separated by this barrier, which provides continuous sealing without mechanical contact. This eliminates the need for periodic maintenance activities such as packing element replacement and grease injection, as the magnetic coupling maintains its sealing function indefinitely without degradation or consumption of sealing materials.
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 system eliminates the need for stuffing boxes, providing a reliable and leak-proof mechanism for power transfer, suitable for high-pressure and H2S environments, enhancing safety and reducing maintenance needs.
Implementation Method 1
The magnetic follower is magnetically coupled to follow movement of the magnetic driver through magnetic interaction across a gap between the magnetic follower and the magnetic driver
Implementation Method 2
an enclosure body having a magnetically transparent wall
Data Source
AI summary
Systems to drive a downhole pump include an enclosure body with a magnetically transparent wall. A magnetic driver or a stationary member with coil windings in slots is disposed outside the enclosure body. A magnetic follower or a movable member with one or more permanent magnets is disposed inside the enclosure body such that the magnetic follower or movable member is exposed to a different environment compared to the magnetic driver or stationary member. The magnetic driver and magnetic follower, or the stationary member and movable member, are separated by a gap containing at least a portion of the magnetically transparent wall. A prime mover is operatively coupled to the magnetic driver. A rod couples the magnetic follower or the movable member to the downhole pump. Movement of the rod with the magnetic follower or the movable member operates the pump.