Mechanical Seal Protector Filtration for ESP Sand Contamination

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Solution Overview

Problem

Prior art mechanical seals in submersible pumping systems are susceptible to failure due to contamination with sand and other particulate solids, which degrades their performance and sealing effectiveness in harsh downhole environments.

Innovation Solution

The introduction of a mechanical seal protector with a filter screen and cap surrounding the mechanical seal, featuring expulsion ports and auxiliary seals, which reduces exposure to contaminants and enhances the durability of the mechanical seal by preventing particulate intrusion and promoting the expulsion of solids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical seal with spring and sealing surfaces is used to prevent fluid migration along the shaft, then sealing effectiveness is improved, but susceptibility to contamination and wear from solid particles increases

Engineering Contradiction:

Improvesealing effectivenessVSAvoidcontamination from solid particles

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A filter screen is introduced as an intermediary component between the contaminated wellbore fluid and the mechanical seal. The filter screen captures solid particles before they can reach and contaminate the mechanical seal's sealing surfaces and spring, thereby protecting the seal while maintaining its sealing effectiveness.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The seal section is divided into separate functional zones: a contaminated fluid zone, a filter zone, and a clean seal zone. This segmentation isolates the mechanical seal from direct exposure to contaminants by creating distinct regions with different functional requirements.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the mechanical seal is exposed to wellbore fluids to maintain sealing function, then fluid separation is achieved, but solid particles accumulate near the seal causing degradation

Engineering Contradiction:

Improvefluid separationVSAvoidmechanical seal service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The filter screen acts as a mediator that allows fluid separation to occur while preventing solid particles from reaching the mechanical seal. This enables the seal to maintain its fluid separation function without the detrimental effect of particle accumulation that would otherwise reduce its service life.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The filter screen performs preliminary action by capturing solid particles before they can reach and accumulate near the mechanical seal. This pre-filtration prevents degradation of the seal components and extends their operational duration.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the mechanical seal components are kept in proper position using spring force, then sealing performance is maintained, but solid particles compromise the spring performance and sealing surfaces

Engineering Contradiction:

Improvesealing performanceVSAvoiddegradation of spring and sealing surfaces

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The filter screen serves as a protective intermediary that prevents solid particles from compromising the spring and sealing surfaces. By filtering out particles before they reach these components, the filter preserves spring performance and sealing surface integrity, maintaining sealing performance without material degradation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The filter screen provides beforehand protection by capturing solid particles that would otherwise cause wear and degradation to the spring and sealing surfaces. This preventive measure cushions the seal components from harmful particle contact, extending their service life.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 mechanical seal protector significantly improves the operational life and reliability of the mechanical seals by preventing contamination and effectively managing solid particles, thereby enhancing the overall performance and longevity of the seal section in submersible pumping systems.

Implementation Method 1

The mechanical seal protector includes a filter screen and a cap that surrounds a portion of the mechanical seal

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Implementation Method 2

The auxiliary seal provides a sealing interface between the stationary cap and the rotatable shaft

Methodology Applied

Scientific EffectSealing:

Implementation Method 3

The cap comprises a plurality of expulsion ports extending through the cap

Methodology Applied

Scientific EffectGravity-driven expulsion: Gravitation

Data Source

PatentUS11365809B2Mechanical seal protector for ESP seal sections

Publication Date: 2022.06.21 BAKER HUGHES ESP INC

AI summary

A seal section for use in a downhole submersible pumping system includes one or more fluid separation mechanisms, a shaft, a mechanical seal chamber and a mechanical seal inside the mechanical seal chamber. The seal section further comprises a mechanical seal protector around the mechanical seal. The mechanical seal protector includes a cap that surrounds a portion of the mechanical seal and a filter screen. The cap may also include one or more expulsion ports extending through the cap. The cap may be stationary or connected to the shaft and configured for rotation.