Anchor System for Thermal Shrinkage in Injection Well Packers

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Solution Overview

Problem

In injection wells, significant temperature changes cause the liner to shrink, leading to potential damage or loss of seal for isolation packers due to thermal stresses, requiring substantial counteracting forces to maintain seal integrity.

Innovation Solution

An isolation assembly with anchors, such as inflatable or telescoping pistons, is mounted on the tubular to resist dimension changes caused by temperature fluctuations, ensuring the packers remain undamaged and maintain sealing integrity by gripping the wellbore.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the liner is used to support packers in injection wells, then the packers can isolate zones for fluid injection, but the liner shrinks due to temperature changes causing loss of packer grip and seal integrity

Engineering Contradiction:

Improvepacker seal integrityVSAvoidthermal shrinkage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The anchor system is deployed in advance to counteract the thermal shrinkage forces before they can damage the packers. The anchor extends to engage the formation, creating a preliminary counteracting force that prevents the liner from shrinking and pulling the packers loose during subsequent temperature changes from fluid injection.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The anchor system provides a counteracting tensile force that balances the thermal contraction forces. By engaging the formation through extended anchor elements, the system creates an opposing force that compensates for the liner shrinkage, preventing loss of packer grip and maintaining seal integrity throughout the injection process.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

2Adaptability or versatility

If large packer spacing is employed, then more zones can be isolated, but the amount of liner shrinkage increases significantly

Engineering Contradiction:

Improvezone isolation capabilityVSAvoidliner shrinkage

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The anchor system divides the liner into anchored and unanchored segments. The anchor elements engage at specific locations along the liner, creating segmented zones where the liner is mechanically supported against thermal shrinkage. This allows large packer spacing for zone isolation while the anchored segments prevent excessive liner shrinkage between packers.

Inventive Principle:

Principle #1Segmentation

3Reliability

If telescoping pistons are used as anchors, then they can be positioned to grab in open hole and resist thermal forces, but the device complexity increases

Engineering Contradiction:

Improvethermal force resistanceVSAvoidanchor mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The anchor system uses dynamic telescoping pistons that can extend and retract as needed. The pistons remain compact during deployment but extend to engage the formation when thermal shrinkage forces are anticipated, providing adaptive support that reduces complexity compared to permanently extended anchors while maintaining reliable thermal force resistance.

Inventive Principle:

Principle #15Dynamics

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 anchors effectively minimize thermal stress-induced damage to packers, maintaining their sealing integrity and preventing axial movement that could compromise the seal, even under substantial temperature differences.

Implementation Method 1

the temperature of the liner pipe that supports the isolation packers or other barriers used to direct the injection flow begins to change to the injection temperature. This usually means that the liner between packers cools and as a result shrinks.

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the liner between packers cools and as a result shrinks. Just how much is a function of the coefficient of thermal expansion or contraction for the given material of the liner and the temperature difference.

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentUS7726407B2Anchor system for packers in well injection service

Publication Date: 2010.06.01 BAKER HUGHES CO

AI summary

An isolation assembly for downhole injection use is described that features at least one isolation device mounted on a tubular so that when injection fluid changes the tubular temperature which can cause a length change in the tubular, an anchor for the tubular is provided to resist such a dimension change. The result is that the isolation device such as a packer can be left undamaged and retaining its sealing integrity. The anchor can be an inflatable or telescoping pistons disposed to grab in open hole. When using telescoping pistons, their placement on the liner and their pattern can meet the desired locations where grip is enhanced. Use of cement inflatable anchors is contemplated as an alternative.