Polysaccharide Microspheres for Controlled Additive Delivery in Drilling Fluids

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Solution Overview

Problem

During wellbore drilling, significant fluid loss occurs due to formation damage and porosity, leading to inefficient operations and the need for treatments that often fail to provide controlled and targeted delivery of additives.

Innovation Solution

Polysaccharide microspheres are used to encapsulate materials for controlled release in wellbore operations, formed through an emulsion-based assembly method and crosslinked with divalent ions, allowing for targeted delivery and stabilization of additives, which can be triggered by external stimuli such as temperature, pH, or shear forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional wellbore fluids are used to treat formation damage, then fluid loss is reduced, but the delivery of additives is uncontrolled and non-targeted

Engineering Contradiction:
Improvecontrolled delivery of additivesVSAvoidcomplexity of delivery system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The treatment fluid is segmented into multiple functional components: polysaccharide microspheres containing encapsulated additives, suspended in a wellbore fluid carrier. This segmentation allows controlled delivery through the dissolution of individual microspheres at target locations, providing reliability without requiring a single complex integrated system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Additives are pre-encapsulated within polysaccharide microspheres before wellbore treatment. This preliminary encapsulation protects the additives during transport and enables controlled release at the target formation, achieving reliable targeted delivery without complex real-time control systems.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If polysaccharide microspheres are used to encapsulate materials for controlled release, then targeted delivery is achieved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveprecision of additive deliveryVSAvoidease of microsphere production
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Polysaccharides serve as intermediary materials that facilitate the encapsulation of hydrophobic additives within water-soluble microsphere structures. This intermediary approach enables precise control over additive release while using well-established polysaccharide manufacturing techniques, balancing manufacturing precision with ease of production.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The manufacturing process utilizes changes in physical parameters (temperature, pH, ionic strength) to control microsphere formation and additive encapsulation. By leveraging parameter changes rather than complex mechanical processes, the system achieves precise additive delivery control while maintaining ease of manufacture through simple environmental adjustments.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If treatments are applied to mitigate fluid loss, then formation damage is reduced, but the treatments often fail to provide controlled and targeted delivery

Engineering Contradiction:
Improveeffectiveness of formation treatmentVSAvoidsimplicity of treatment application
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The treatment system transitions from static additive delivery to dynamic controlled release. Polysaccharide microspheres dissolve dynamically in response to downhole conditions (temperature, pH, ionic strength), enabling reliable targeted treatment of formation damage while maintaining operational simplicity through passive response to environmental stimuli rather than active control mechanisms.

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 polysaccharide microspheres effectively reduce fluid loss by providing controlled release of additives, enhancing the stability and effectiveness of wellbore treatments, and allowing for targeted delivery of chemicals and rheological modifiers, thereby improving drilling efficiency and reducing formation damage.

Implementation Method 1

when the aqueous polysaccharide solution is mixed with the oil, the solution phase may separate to produce spheres

Methodology Applied
Scientific EffectPhase separation: Phase Change

Implementation Method 2

adding the ion source creates ionic bonding at the surface of the water-in-oil droplets to create a hardened shell or crosslinkage

Methodology Applied
Scientific EffectIonic bonding: Chemical Bonding

Implementation Method 3

forming an internal phase containing a polysaccharide encapsulant in a water-in-oil or invert emulsion

Methodology Applied
Scientific EffectEmulsion: Emulsion

Data Source

PatentUS11820934B2Microsphere compositions and methods for production in oil-based drilling fluids
Publication Date: 2023.11.21 SCHLUMBERGER TECH CORP

AI summary

A method includes admixing an aqueous polysaccharide solution into an oleaginous base fluid, and adding a divalent ion source to produce one or more polysaccharide microspheres.