Gas Slug Avoidance via Passive Check Valves

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Solution Overview

Problem

Current methods for reducing gas slugging in deviated wells, such as mechanical valves and gas-permeable membranes, are unreliable and inefficient due to environmental challenges and power supply issues, leading to reduced pumping rates and pump damage.

Innovation Solution

A gas mitigation system with a well zone isolation device, back pressure control module, and gas vent line that maintains a gas pocket upstream of the submersible pumping system, using a liquid intake line to manage gas and liquid flow, and a back pressure control module to adjust gas pressure and prevent slug formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical valves are used in gas vent tube, then gas can be vented from wellbore, but reliability deteriorates due to harsh downhole environment and power supply requirements

Engineering Contradiction:

Improvevalve reliabilityVSAvoidpower supply requirement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the complex power supply and control systems from the downhole environment by extracting the active valve mechanism to the surface. The gas vent tube uses passive check valves that automatically open based on pressure differential alone, eliminating the need for downhole power supplies while maintaining gas venting functionality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The check valves are designed to automatically respond to pressure conditions without external control. When gas pressure exceeds liquid pressure, the valve self-actuates to open and vent gas, then self-closes when pressure equalizes, providing reliable operation without power supply or complex control systems.

Inventive Principle:

Principle #25Self-service

2Reliability

If gas-permeable membranes are used, then gas passage is enabled, but reliability deteriorates due to fouling from sand and debris

Engineering Contradiction:

Improvemembrane reliabilityVSAvoidfouling from sand and debris

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs simple check valves that can be easily replaced if needed, rather than complex gas-permeable membranes that foul and require replacement. The valves are designed to withstand harsh conditions and can be maintained or replaced as part of routine well maintenance, providing more reliable long-term operation.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If multiple mechanical valves are distributed throughout wellbore, then gas venting coverage is improved, but device complexity increases due to power supply to each valve

Engineering Contradiction:

Improvegas venting coverageVSAvoidpower supply system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The gas vent tube with distributed check valves provides universal gas venting capability throughout the wellbore without requiring individual power supplies. Each check valve independently responds to local pressure conditions, providing distributed gas venting coverage while maintaining system simplicity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Productivity

If gas pressure is allowed to build up, then gas can be vented when critical pressure is reached, but productivity deteriorates due to reduced maximum fluid entry rate

Engineering Contradiction:

Improvefluid entry rateVSAvoidgas pressure buildup

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The check valves provide continuous feedback-based pressure relief by automatically opening when gas pressure exceeds liquid pressure at any location along the vent tube. This prevents excessive pressure buildup that would reduce fluid entry rate, while maintaining the ability to vent gas continuously as it forms, optimizing overall productivity.

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

Effectively reduces gas slugging by controlling gas and liquid flow, maintaining pumping efficiency and extending pump operational lifetime by preventing gas slug formation and ensuring reliable operation in harsh downhole environments.

Implementation Method 1

a back pressure control module configured to maintain a pocket of gas adjacent the upstream side of the well zone isolation device

Methodology Applied

Scientific EffectGas pressure control: Pressure Increase

Implementation Method 2

A liquid intake line extends through the well zone isolation device from an area of the wellbore adjacent the downstream side of the well zone isolation device to an area of the wellbore upstream from the pocket of gas

Methodology Applied

Scientific EffectPhase separation: Two-Phase Flow

Data Source

PatentUS11802469B2ESP gas slug avoidance system

Publication Date: 2023.10.31 BAKER HUGHES ESP INC

AI summary

A gas mitigation system for controlling the amount of gas that reaches a submersible pumping system deployed in a wellbore includes a well zone isolation device disposed in the wellbore between the submersible pumping system and a gas collecting region. The gas mitigation system further includes a back pressure control module and a gas vent line extending from the gas collecting region through the well zone isolation device to the back pressure control module. A liquid intake line extends from the well zone isolation device to an area of the wellbore upstream from the gas collecting region.