Hermetic Downhole Electric Machine Isolation With Magnetic Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Downhole electric machines in wells are prone to contamination and pressure issues, leading to reduced operational lifespan and efficiency, especially when exposed to high-speed operations and varying well reservoir conditions.
Innovation Solution
A hermitically sealed, high-speed downhole-type electric machine with a housing flooded with an incompressible fluid to isolate the electric rotor, stator, and magnetic coupling from wellbore fluids, using magnetic or mechanical bearings for support and a magnetic coupling to transmit rotational force, maintaining pressure equivalence with the wellbore environment and providing lubrication and cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electric machine is exposed to wellbore fluids, then it can operate in the downhole environment, but it suffers from contamination and reduced operational lifespan
Solution Approach 1:
The electric machine is divided into isolated segments: the motor assembly (rotor and stator) is separated from the wellbore environment by a hermetically sealed housing, while the magnetic coupling transmits power across the isolation boundary. This segmentation allows the motor to operate in a protected internal environment while still functioning in the downhole application.
Solution Approach 2:
A magnetic coupling acts as an intermediary between the isolated motor assembly and the external wellbore environment. It transmits rotational force and torque across the hermetic seal without requiring physical penetration, thereby protecting the motor from contaminants while maintaining power transmission to the pump or compressor.
2Reliability
If the housing is hermetically sealed to protect components, then reliability improves, but pressure differential creates mechanical support requirements
Solution Approach 1:
The patent replaces mechanical support structures with a magnetic coupling system that can transmit torque through the hermetic seal without mechanical contact. This substitution eliminates the need for complex mechanical seals and support structures that would be required to handle pressure differentials, reducing overall device complexity while maintaining protection.
3Power
If the machine operates at higher speeds, then output horsepower increases, but mechanical support and bearing requirements increase
Solution Approach 1:
The magnetic coupling system replaces mechanical bearings and support structures that would be required to handle high-speed rotation. By using magnetic fields for torque transmission and support, the system can operate at higher speeds without the friction and mechanical wear limitations of traditional bearing systems, thereby increasing power output without proportionally increasing mechanical support complexity.
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 effectively protects the electric machine components from contaminants, maintains operational efficiency, and reduces mechanical support requirements, enabling higher speed and output horsepower while extending the lifespan of the machine.
Implementation Method 1
The fluid in the housing lubricates bearings radially and axially supporting the electric rotor within the electric stator
Implementation Method 2
The fluid in the housing cools the electric stator and bearings located within the housing
Implementation Method 3
A magnetic coupling is attached to an end of the electric rotor. The magnetic coupling is configured to transmit rotational force to or from a separate rotational device
Data Source
AI summary
An electric stator surrounds an electric rotor. A magnetic coupling is attached to an end of the electric rotor. The magnetic coupling is configured to transmit rotational force to or from a separate rotational device. A housing surrounds and isolates the electrical rotor, the electric stator, and a portion of the magnetic coupling, from a wellbore fluid. The housing is flooded with an incompressible fluid. A pressure within the housing is substantially the same or lower than a pressure within a wellbore environment.