Swellable Polymer Particles for Oilfield Water Conformance Control

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Solution Overview

Problem

Water production in mature oilfields is a significant issue due to 'thief zones' causing preferential water flow through more porous regions, leading to excess water production, corrosion, scale buildup, and increased environmental concerns, which can shut down wells.

Innovation Solution

A composition of swellable particles with crosslinkable polymer chains and an assembling agent that associates with the polymer chains upon exposure to fluid, allowing the particles to swell and form a thermo-stable gel, which can be designed to control fluid flow and accumulate in fractures, reducing water production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If water is injected to push oil from underground oil fields, then oil production is improved, but water preferentially travels through more porous regions causing excess water production and reduced sweep efficiency

Engineering Contradiction:

Improveoil productionVSAvoidwater production

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by using swellable particles with specific pore-size selectivity that target and plug only the larger thief zones while leaving smaller productive pores open. The particles are designed to swell to specific sizes that correspond to fracture and thief zone dimensions, creating localized plugging action in high-permeability regions without affecting overall reservoir productivity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes porous swellable particles that can absorb fluid and expand in size. These particles are specifically designed with pore structures that allow them to swell to dimensions suitable for plugging thief zones. The porous nature enables controlled swelling behavior that can be tuned to match specific reservoir pore size distributions.

Inventive Principle:

Principle #31Porous materials

2Quantity of substance

If swellable particles are used to plug thief zones, then water production is reduced, but particle size and swelling mechanism must be precisely controlled to avoid blocking productive zones

Engineering Contradiction:

Improvewater productionVSAvoidparticle size control

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling the initial particle size, swelling capacity, and crosslinking density of the swellable particles. These parameters are optimized so that particles swell to specific target sizes that plug thief zones without blocking productive pores. The swelling behavior is tuned by adjusting polymer composition, crosslinking agents, and particle formulation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite swellable particles composed of multiple polymer components with different swelling characteristics. This composite structure allows fine-tuning of swelling behavior and mechanical properties. The composite nature enables particles to exhibit controlled swelling rates and final sizes that can be precisely matched to reservoir pore dimensions.

Inventive Principle:

Principle #40Composite materials

3Reliability

If particles accumulate in fractures to control fluid flow, then conformance control is improved, but fluid segregation and chromatographic problems may occur

Engineering Contradiction:

Improveconformance controlVSAvoidfluid homogeneity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-coating the swellable particles with materials that reduce fluid segregation and chromatographic effects. This pre-treatment ensures that particles maintain compositional stability during migration and accumulation in fractures. The coating is applied before injection to prevent unwanted interactions with reservoir fluids during transport.

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 swellable particles effectively reduce water production by swelling and forming a strong gel that accumulates in fractures, minimizing fluid segregation and chromatographic problems, thereby enhancing oil recovery and reducing corrosion and environmental concerns.

Implementation Method 1

a fluid capable of swelling the polymer chains

Methodology Applied

Scientific EffectSwelling: Absorption (physical)

Implementation Method 2

crosslinkable polymer chains, and the assembling agent is one that will associate with the polymer chains

Methodology Applied

Scientific EffectCrosslinking: Chemical Bonding

Data Source

PatentUS11549048B2Re-assembling polymer particle package for conformance control and fluid loss control

Publication Date: 2023.01.10 THE CURATORS OF THE UNIVERSITY OF MISSOURI

AI summary

This invention is broadly concerned with compositions and processes for oilfield applications. More specifically, this invention relates to novel polymer constructed packages that, when pumped into a petroleum well, provide tunable characteristics of transformation and delayed self-assembly with each other under reservoir conditions to yield strong, elastic, bulk gel materials. The compositions comprise a polymer, assembling agents, and optional additives used for the re-assembly stage are uniformly-distributed within the initial gel particles. The polymer particle packages absorb water and swell upon exposure to water, thus exposing the “assembling agents” that enable re-assembly. Both swelling and re-assembly are proportionally controlled via compositions to be tunable to allow functional dispersion and subsequent self-assembly under various reservoir conditions.