Dendritic Polymer Filtrate Control in High-Temperature, High-Salt Drilling

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Solution Overview

Problem

Existing polymer filtrate loss reducers face challenges in high temperature and high salinity environments, with issues in viscosity, rheological properties, and suspension stability, while also requiring improved filtrate loss reduction and wellbore stability.

Innovation Solution

A dendritic polyester-based polymer is developed through free radical polymerization, incorporating non-ionic and anionic monomers, with a compact structure and hydroxyl groups, providing enhanced filtrate loss reduction and blocking performance, along with improved temperature and salt resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If linear polymer filtrate loss reducers are used, then they provide basic filtrate loss reduction, but they exhibit poor temperature resistance and salt resistance

Engineering Contradiction:
Improvetemperature and salt resistanceVSAvoidfiltrate loss reduction effectiveness
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent employs composite materials by combining dendritic polyester core structure with grafted monomer units (acrylamide, AMPS, and crosslinking agents) to create a hybrid polymer architecture that integrates the thermal stability of dendritic structures with the functional properties of sulfonic acid groups and amide units, achieving both high temperature/salt resistance and effective filtrate loss reduction

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the molecular architecture parameter from linear to dendritic structure with controlled generation levels (G1, G2, G3), molecular weight, and grafting density, which fundamentally alters the polymer's thermal and salinity stability while maintaining or enhancing its filtrate loss reduction capability through optimized structural parameters

Inventive Principle:
Principle #35Parameter changes

2Reliability

If polymer concentration is increased to improve blocking performance, then blocking effect is enhanced, but viscosity and rheological properties deteriorate

Engineering Contradiction:
Improveblocking performanceVSAvoidviscosity and rheological properties
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the polymer structure into a compact dendritic core with multiple generations of branching and grafted functional arms, creating a modular architecture that provides effective blocking at lower concentrations without excessive viscosity increase, as the segmented dendritic structure prevents entanglement while maintaining blocking capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from one-dimensional linear polymer chains to three-dimensional dendritic structures with radial symmetry, allowing the polymer to occupy space more efficiently and provide blocking performance through spatial distribution rather than chain entanglement, thereby improving blocking at lower concentrations with better rheological properties

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If high molecular weight polymer is used to enhance filtrate loss reduction, then blocking and filtration control improve, but suspension stability and rheological properties worsen

Engineering Contradiction:
Improvefiltrate loss reductionVSAvoidsuspension stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent creates a composite dendritic polymer structure combining a rigid dendritic polyester core with flexible grafted polymer arms containing sulfonic acid groups and amide units, where the core provides molecular weight and blocking capability while the grafted arms provide colloidal stability and resistance to aggregation in saline environments

Inventive Principle:
Principle #40Composite materials

4Quantity of substance

If conventional polymer structures are used, then manufacturing is simple, but filtrate loss reduction and blocking performance are insufficient

Engineering Contradiction:
Improvefiltrate loss reduction and blocking performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by first synthesizing the dendritic polyester core structure with controlled generation levels and functional groups before grafting the monomer units, allowing precise control over the final polymer's molecular weight, branching density, and functional group distribution to optimize performance while streamlining the manufacturing process through staged synthesis

Inventive Principle:
Principle #10Preliminary 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

The dendritic polymer effectively reduces filtrate loss, enhances wellbore stability, and maintains structural integrity under high temperature and high salinity conditions, offering superior blocking and filtrate loss reduction compared to linear polymers.

Implementation Method 1

promote formation of a thin and dense filter cake with low permeability on the wellbore wall, thereby reducing invasion of filtrate into the stratum

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

A dendritic polyester-based polymer is developed through free radical polymerization, incorporating non-ionic and anionic monomers

Methodology Applied
Scientific EffectFree radical polymerization: Photopolymerisation

Implementation Method 3

lowering the probability of shale hydration and swelling in enhancing wellbore stability

Methodology Applied
Scientific EffectHydrogen bonding:

Data Source

PatentEP4296293B1Dendritic polymer, and preparation method therefor and application thereof
Publication Date: 2025.08.27 CHINA PETROLEUM & CHEMICAL CORP
  • EP4296293B1 patent drawingFigure 1
  • EP4296293B1 patent drawingFigure 2~3
  • EP4296293B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to a dendritic polymer, and a preparation method therefor and a use thereof. The dendritic polymer contains a dendritic polyester as a core, and a plurality of arms obtained by means of polymerization of an alkenyl monomer; the root-mean-squere radius of gyration of the dendritic polymer does not exceed 100 nm; and the alkenyl monomer contains a non-ionic monomer and an anionic monomer. According to the dendritic polymer of the present disclosure, the dendritic polyester is used as the core, the polymeric segments formed by a monomer generally used for synthesizing a filtrate loss reducer are used as the arms, and the dendritic polymer is obtained by means of free radical polymerization; and compared with a linear polymer, in the case that the molecular weight is identical, the dendritic polymer of the present disclosure has a smaller root-mean-square radius of gyration, and is more compact in structure, so that the dendritic polymer is used in a drilling fluid, has a stronger filtrate loss reduction function, has a blocking performance, and also has better temperature resistance and salt resistance.