Lateral Isolation Chamber for Subsea Motor Protector Length Reduction

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Solution Overview

Problem

Conventional electric submersible pumps (ESPs) face challenges when deployed subsea, particularly due to their length, which complicates handling and increases operational costs, as they require larger vessels for intervention operations and are more complex to manage.

Innovation Solution

A motor protector for ESPs is designed with a housing, radial bearings, thrust bearings, and shaft seals, along with an isolation chamber that reduces the length of the ESP by allowing pressure equalization between extracted fluids and motor oil, thereby protecting the motor from contamination and enabling thermal expansion, and absorbing shaft thrust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ESP design is used for subsea deployment, then motor protection from contamination is achieved, but ESP length increases making handling more complex and requiring larger vessels

Engineering Contradiction:
Improvemotor protectionVSAvoidhandling complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The isolation chamber is positioned laterally adjacent to the motor housing rather than extending axially, transforming the pressure equalization function from a longitudinal arrangement to a lateral one. This dimensional change reduces the axial length of the ESP while maintaining the isolation and pressure equalization functions, thereby improving handling ease without compromising motor protection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If conventional ESP design is used for subsea deployment, then motor protection from contamination is achieved, but larger vessels are required for intervention operations

Engineering Contradiction:
Improvemotor protectionVSAvoidvessel size requirement
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

By positioning the isolation chamber laterally adjacent to the motor housing rather than extending axially, the overall length of the ESP assembly is reduced. This dimensional reconfiguration allows the same motor protection functionality to be achieved with a more compact device that can be handled by smaller vessels, reducing operational costs and resource requirements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of moving object

If isolation chamber is positioned laterally, then ESP length is reduced, but pressure equalization between extracted fluid and motor oil must be maintained

Engineering Contradiction:
ImproveESP lengthVSAvoidpressure equalization control
Core Design Contradiction:
Length of moving objectVSStress or pressure

Solution Approach 1:

The isolation chamber acts as an intermediary pressure equalization zone positioned laterally between the extracted fluid environment and the motor oil. It includes a fluid communication path with the suction chamber and an expansion space that allows pressure equalization through thermal expansion and contraction, maintaining pressure balance without requiring axial extension of the ESP.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The isolation chamber is designed to accommodate pressure variations through thermal expansion and contraction of the motor oil. By allowing temperature-induced volume changes in the isolation chamber, the system dynamically adjusts pressure equalization between the extracted fluid and motor oil, maintaining equilibrium without compromising the compact lateral design.

Inventive Principle:
Principle #35Parameter changes

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 results in a shorter ESP length, reducing operational costs and simplifying handling, as ESPs can be managed with smaller vessels, while maintaining protection from contaminants and facilitating easier subsea deployment.

Implementation Method 1

The isolation chamber is configured to equalize a pressure of the second fluid with a pressure of the first fluid by allowing thermal expansion of the second fluid

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3358130B1Motor protector of an electric submersible pump and an associated method thereof
Publication Date: 2023.05.03 GENERAL ELECTRIC CO
  • EP3358130B1 patent drawingFigure 1
  • EP3358130B1 patent drawingFigure 2
  • EP3358130B1 patent drawingFigure 3

AI summary

A motor protector 142 includes a housing 210 and a rotatable shaft 318 disposed within the housing 210 and a plurality of radial bearings 308,310 coupled to the rotatable shaft 318, for supporting the rotatable shaft 318 against the housing 210. The motor protector 142 further includes a thrust bearing 322 coupled to the rotatable shaft 318, for supporting the rotatable shaft 318 against the housing 210. The motor protector 142 also includes a shaft seal 302 coupled to the rotatable shaft 318, and configured to seal a first portion from a second portion of the housing. The motor protector 142 also includes an isolation chamber 208, coupled substantially lateral to the housing 210 and configured to separate a first fluid and a second fluid via the housing 210.