Micro-crosslinked Gel Particulate Suspension Friction

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Solution Overview

Problem

Conventional gelled treatment fluids used in subterranean applications face challenges such as reduced particulate suspension at elevated temperatures, increased pipe friction, and residue left in the formation, which affect well productivity and ease of fluid removal.

Innovation Solution

The development of micro-crosslinked gels, which comprise small, permanently crosslinked volumes (micro-domains), allowing for improved particulate suspension and reduced pipe friction at elevated temperatures, and minimizing residue in the formation by maintaining viscosity and preventing particulate clustering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional gelled treatment fluids are used to suspend particulates, then viscosity is increased, but pipe friction increases and particulate suspension is reduced at elevated temperatures

Engineering Contradiction:

Improveparticulate suspension capabilityVSAvoidpipe friction

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The gel structure is segmented into discrete micro-crosslinked domains (1-100 micrometers in size) distributed throughout the treatment fluid. Each micro-domain acts as an independent suspension zone, collectively providing enhanced particulate suspension capability while maintaining lower overall fluid viscosity compared to conventional gels, thereby reducing pipe friction during injection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the crosslinking parameter from macro-scale continuous crosslinking to micro-scale discrete crosslinking. This parameter change in crosslinking architecture allows the fluid to maintain adequate viscosity for particulate suspension at elevated temperatures while reducing the overall viscosity enough to lower pipe friction during injection operations.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If gelling agents are crosslinked to increase viscosity, then particulate suspension improves, but residue is left in the formation affecting productivity

Engineering Contradiction:

Improveparticulate suspension capabilityVSAvoidformation residue

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The micro-crosslinked gel domains are designed to be temporary and degradable. After performing their suspension function during injection and placement, these micro-domains break down into smaller molecules that can be easily flushed from the formation, leaving minimal to no residue that would harm formation productivity or block pores.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The gel system is designed to discard its viscous structure after use. The micro-crosslinked domains degrade and break down after completing the particulate suspension and placement function, allowing the treatment fluid to revert to a low-viscosity state that can be easily recovered and removed from the formation without leaving harmful residues.

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If gelling agents are used to maintain viscosity at elevated temperatures, then particulate suspension is improved, but fluid removal becomes difficult

Engineering Contradiction:

Improveparticulate suspension capabilityVSAvoidfluid removal

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The treatment fluid exhibits dynamic viscosity characteristics where the micro-crosslinked gel domains are active during injection and placement (maintaining high viscosity for particulate suspension) but degrade and become inactive during the removal phase (reverting to low viscosity for easy pumpout). This temporal dynamic allows the same fluid to satisfy opposing requirements at different stages of the operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The gel system undergoes periodic transformation between high-viscosity and low-viscosity states. During the injection and placement phase, micro-crosslinking creates high viscosity for particulate suspension. During the removal phase, degradation breaks down the crosslinks, reducing viscosity to facilitate easy fluid recovery. This periodic action resolves the contradiction between suspension capability and fluid removal ease.

Inventive Principle:

Principle #19Periodic action

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

Micro-crosslinked gels effectively suspend particulates for extended periods at high temperatures, reducing pipe friction and minimizing residue, thus enhancing well productivity and ease of fluid removal.

Implementation Method 1

Micro-crosslinked gels effectively suspend particulates for extended periods at high temperatures

Methodology Applied

Scientific EffectViscosity:

Implementation Method 2

improved particulate suspension and reduced pipe friction at elevated temperatures

Methodology Applied

Scientific EffectShear thinning: Shear Thinning

Data Source

PatentUS7814980B2Micro-crosslinked gels and associated methods

Publication Date: 2010.10.19 HALLIBURTON ENERGY SERVICES INC

AI summary

Methods of forming and utilizing micro-crosslinked gels are disclosed, including a method comprising: providing a micro-crosslinked gel that comprises micro-domains; and placing the micro-crosslinked gel into a subterranean formation via a well bore penetrating the formation at a desired pressure. In another aspect, the invention provides compositions that include a micro-crosslinked gel comprising a jigsaw configuration of micro-domains and particulates.