High-Temperature Drilling Fluid Plugging Agent via Double-Crosslinking

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Solution Overview

Problem

Conventional drilling fluids face challenges in high-temperature environments due to the lack of sulfonated materials, leading to issues like well wall collapse, filtrate loss, and poor plugging performance, which are not adequately addressed by existing alternatives.

Innovation Solution

A novel, environment-friendly high-temperature resistant water-based drilling fluid plugging anti-sloughing agent with a core-shell structure is developed, utilizing a double-crosslinking network formed by combining chemical cross-linking agents and silane coupling agents, which enhances temperature resistance and adsorption capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If sulfonated asphalt is used as plugging anti-sloughing material, then temperature resistance and plugging performance are improved, but environmental protection performance deteriorates and chrominance increases

Engineering Contradiction:
Improvetemperature resistanceVSAvoidenvironmental protection performance
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the sulfonated asphalt component from the drilling fluid system, replacing it with alternative materials that do not contain sulfonated substances. This extraction eliminates the environmental harm and chrominance issues while maintaining the essential plugging and temperature resistance functions through different chemical compositions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters of the plugging anti-sloughing agent by replacing sulfonated asphalt with non-sulfonated alternatives such as modified polymers and inorganic materials. This parameter change maintains the functional performance (plugging and temperature resistance) while improving environmental compatibility and reducing chrominance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If sulfonated asphalt is used as plugging anti-sloughing material, then plugging performance is improved, but ease of operation deteriorates due to narrow softening temperature window

Engineering Contradiction:
Improveplugging performanceVSAvoidsoftening temperature window
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent employs composite materials consisting of multiple components including modified polymers, inorganic particles, and additives. This composite structure combines materials with different thermal properties, creating a plugging agent that maintains its structural integrity and plugging performance across a broader temperature range, avoiding the narrow softening window problem of pure sulfonated asphalt.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by creating a heterogeneous composite where different components serve specific functions: some materials provide thermal stability, others provide plugging capability, and additional components adjust the softening characteristics. This localized functional distribution within the composite enables the overall system to maintain plugging performance across a wider temperature window.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If sulfonated materials are removed from drilling fluid system, then environmental protection performance is improved, but reliability deteriorates due to well wall collapse and filtrate loss

Engineering Contradiction:
Improveenvironmental protection performanceVSAvoidwell wall stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent utilizes biodegradable and environmentally friendly materials that can perform their plugging and protective function temporarily during the drilling operation, then degrade harmlessly. These materials provide the necessary well wall stabilization and filtrate loss control during the drilling process while ensuring environmental safety, replacing the persistent but harmful sulfonated materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical and physical parameters of the alternative materials to match or exceed the performance of sulfonated materials. By adjusting molecular weight, cross-linking density, particle size distribution, and surface properties of the non-sulfonated alternatives, the patent achieves equivalent well wall stability and filtrate loss control without the environmental harm of sulfonated compounds.

Inventive Principle:
Principle #35Parameter changes

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 agent effectively reduces filtrate loss and maintains plugging and anti-sloughing performance at high temperatures up to 200°C, offering improved adaptability and environmental sustainability compared to traditional sulfonated asphalt.

Implementation Method 1

combining chemical cross-linking agents and silane coupling agents to form a double-crosslinking network structure

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Implementation Method 2

can generate a strong adsorption effect with a rock matrix, and can delay the hydration dispersion of shale particles to play an anti-sloughing effect when being adsorbed on a mud shale interface

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentUS11072738B2Environment-friendly high-temperature resistant water-based drilling fluid plugging anti-sloughing agent, preparation method thereof and the water-based drilling fluid
Publication Date: 2021.07.27 CHINA UNIV OF PETROLEUM (EAST CHINA)

AI summary

The present disclosure provides a preparation method of an environment-friendly high-temperature resistant water-based drilling fluid plugging anti-sloughing agent, the preparation method comprises the following steps: mixing and emulsifying a styrene monomer, an acrylic monomer and an emulsifier MS-1 aqueous solution to prepare a pre-polymerization emulsion; dispersing hydrophilic monomer, cationic monomer and an emulsifier MS-1 in water, adjusting the pH to be within a range of 6.5-8.5, then adding mixed monomers of the styrene monomer and acrylic monomer to blend and emulsify to prepare a post-polymerization emulsion; adding a first cross-linking agent and a first initiator into the pre-polymerization emulsion, uniformly dispersing the mixture and carrying out reaction; subsequently dropwise adding the post-polymerization emulsion, adding a second cross-linking agent and a second initiator, uniformly dispersing the mixture and then continuously carrying out reaction, drying and crushing the reaction product to prepare the plugging anti-sloughing agent.