Well Fluid Contamination Detection in Submersible Pump Seals

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Solution Overview

Problem

Electrical submersible pump assemblies in hydrocarbon wells often fail due to well fluid leakage into the motor, leading to costly and time-consuming retrieval and replacement, with existing solutions like secondary pumps facing contamination risks before activation.

Innovation Solution

Incorporating sensors in the seal section and motor to detect contamination of motor oil by well fluid, using a primary and secondary pump assembly setup with a buffer fluid in the secondary pump, and employing light-based sensors to monitor for well fluid encroachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a secondary pump assembly is installed as backup, then pump assembly reliability is improved, but the risk of well fluid contamination to the buffer fluid increases before activation

Engineering Contradiction:

Improvepump assembly reliabilityVSAvoidwell fluid contamination

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent installs sensors in the secondary pump assembly before activation to detect well fluid encroachment on the buffer fluid. This preliminary detection capability allows operators to identify contamination risks before they compromise the pump, enabling proactive maintenance or switching to the secondary pump before damage occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces sensors as intermediary detection devices between the well fluid and the buffer fluid in the secondary pump assembly. These sensors act as early warning systems that detect the presence of well fluid encroachment before it can cause significant contamination or damage to the buffer fluid and pump components.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If shaft seals are used to prevent well fluid entry, then motor protection is improved, but seal leakage eventually occurs causing pump assembly failure

Engineering Contradiction:

Improvemotor protectionVSAvoidseal service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent installs sensors in the seal section to detect well fluid encroachment on motor oil before it reaches the motor. This early detection allows operators to identify seal degradation and potential failure before actual motor contamination occurs, enabling timely maintenance or pump replacement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback system where sensors continuously monitor the seal section for well fluid presence and transmit this information to operators. This feedback loop enables real-time monitoring of seal performance and early warning of seal failure, allowing proactive maintenance decisions.

Inventive Principle:

Principle #23Feedback

3Loss of information

If pump assembly retrieval is performed for failure analysis, then failure cause identification is improved, but operational downtime and costs increase

Engineering Contradiction:

Improvefailure cause identificationVSAvoidoperational downtime

Core Design Contradiction:

Loss of informationVSLoss of time

Solution Approach 1:

The patent implements self-diagnostic capability through sensors that automatically detect and report well fluid encroachment conditions. The sensors monitor for contamination events and provide early warning signals, allowing the pump assembly to essentially diagnose its own health status without requiring retrieval for analysis.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent establishes a feedback system where sensors continuously monitor pump assembly conditions and provide real-time information about well fluid encroachment. This feedback enables operators to identify failure causes remotely without retrieving the pump, significantly reducing operational downtime.

Inventive Principle:

Principle #23Feedback

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

Early detection of well fluid contamination allows for timely maintenance or switch to secondary pumps, reducing downtime and maintenance costs by identifying leaks and preventing damage to internal components.

Implementation Method 1

employing light-based sensors to monitor for well fluid encroachment

Methodology Applied

Scientific EffectLight-based detection: Absorption Spectroscopy

Data Source

PatentUS9441633B2Detection of well fluid contamination in sealed fluids of well pump assemblies

Publication Date: 2016.09.13 BAKER HUGHES CO

AI summary

A submersible well pump assembly include a rotary pump driven by an electrical motor. A seal section operably connects between the motor and the pump for reducing a pressure differential between motor oil in the motor and well fluid surrounding the pump assembly. The pump assembly contains a sealed fluid. A sensor mounted to the well pump assembly detects contamination of the sealed fluid by well fluid encroaching into contact with the sealed fluid. The sensor may be mounted in the motor or the seal section to detect well fluid contamination of motor oil. The sensor may be mounted in a secondary pump that has that has temporary barriers to block the entry of well fluid into a buffer fluid contained in the secondary pump while the secondary pump is in a storage condition within a well.