Expandable Packer Inner Skin Design for Creep Resistance

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Solution Overview

Problem

Existing downhole packer systems face challenges in maintaining sealing integrity and reducing material deformation (creeping) under high temperature and pressure conditions, which affects their longevity and performance during formation fluid sampling in wellbores.

Innovation Solution

An expandable packer assembly with an inner packer having a greater axial length than the outer skin, where inflation of the inner packer causes the outer skin to expand and seal against the wellbore walls, while an articulated protector or flowline protectors prevent the outer skin from creeping by blocking contact with the wellbore walls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer skin is made longer to improve sealing coverage, then sealing capability is improved, but material deformation (creeping) increases under high temperature and pressure

Engineering Contradiction:

Improvesealing capabilityVSAvoidmaterial deformation

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The packer assembly is divided into two distinct sealing components: an outer skin and an inner packer. The outer skin provides initial sealing coverage, while the inner packer serves as a backup sealing element. This segmentation allows each component to have optimized dimensions and material properties, reducing the need for excessive outer skin length that would cause creeping.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner packer is positioned inside the outer skin, creating a nested configuration. When the outer skin fails or deforms under high temperature and pressure, the inner packer can be inflated to provide secondary sealing. This nested arrangement ensures redundant sealing capability without requiring the outer skin to be excessively long, thereby reducing material deformation.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Stability of the object's composition

If the outer skin is made shorter to reduce material deformation, then material stability is improved, but sealing coverage is reduced

Engineering Contradiction:

Improvematerial deformationVSAvoidsealing capability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

Different sections of the packer assembly have different functions and properties. The outer skin provides initial sealing with optimized length to minimize creeping, while the inner packer provides backup sealing capability. This local differentiation allows each component to be optimized for its specific function, ensuring adequate sealing coverage without excessive material deformation.

Inventive Principle:

Principle #3Local quality

3Reliability

If the inner packer axial length is greater than the outer skin axial length, then backup sealing capability is improved, but device complexity increases

Engineering Contradiction:

Improvebackup sealing capabilityVSAvoidpacker assembly structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The inner packer is positioned inside the outer skin, creating a nested configuration that provides backup sealing capability. The inner packer's greater axial length ensures it extends beyond the outer skin's sealing zone, providing redundant sealing if the outer skin fails. This nested design, while adding a component, uses a straightforward concentric arrangement that minimizes overall structural complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The inner packer serves multiple functions: it provides backup sealing capability, can be inflated independently if needed, and its greater axial length ensures coverage beyond the outer skin's sealing zone. This multi-functionality justifies the additional component while maintaining reasonable device complexity through efficient design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enhances the sealing capability and durability of the packer assembly by reducing material deformation, thereby improving the longevity and performance of the packer in various wellbore conditions, allowing for effective fluid collection and sampling.

Implementation Method 1

inflation of the inner packer causes the outer skin to expand

Methodology Applied

Scientific EffectPressure increase: Pressure Increase

Implementation Method 2

inflation of the inner packer causes the outer skin to expand

Methodology Applied

Scientific EffectElastic expansion: Elasticity

Implementation Method 3

the outer skin seals against walls of the wellbore

Methodology Applied

Scientific EffectPressure sealing: Pressure Increase

Data Source

PatentUS10370934B2Systems and methods for an expandable packer

Publication Date: 2019.08.06 SCHLUMBERGER TECH CORP

AI summary

The present disclosure relates to a system that includes a downhole packer assembly that includes an outer skin having a first axial length and an inner packer having a second axial length greater than the first axial length. The inner packer is disposed within the outer skin such that inflation of the inner packer causes the outer skin to expand.