Salt-Tolerant Polymer Microsphere Plugging Agent
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Solution Overview
Problem
Existing polymer microsphere plugging agents lack salt tolerance and exhibit high interfacial tension, which hampers their effectiveness in deep profile control and water plugging in oilfields with high salinity and heterogeneity.
Innovation Solution
A salt-tolerant polymer microsphere plugging agent is developed using a preparation method involving white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, and hydrophilic surfactants through inverse phase emulsion polymerization, achieving ultra-low interfacial tension and enhanced salt tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polymer microsphere plugging agents are used, then they can perform deep profile control and water plugging, but they exhibit high interfacial tension and low salt tolerance
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer microsphere by incorporating specific functional groups (carboxyl, hydroxyl, amine) and adjusting the monomer ratio to achieve ultra-low interfacial tension (10^-3 mN/m) and high salt tolerance (50000 mg/L), directly resolving the contradiction between plugging effectiveness and interfacial tension/salt tolerance
Solution Approach 2:
The patent creates a composite polymer microsphere structure combining multiple functional monomers (acrylamide, acrylic acid, vinylamine hydrochloride) with crosslinking agents, forming a composite material that simultaneously achieves low interfacial tension, high salt tolerance, and effective plugging performance
2Reliability
If existing plugging agents are used in high salinity environments, then they can provide temporary plugging, but they gel in the oil layer reducing relative permeability of oil phase
Solution Approach 1:
The patent applies local quality by making the polymer microsphere surface hydrophobic through specific functional groups, enabling the microsphere to selectively interact with water rather than oil, thus providing plugging in water channels without gelling in the oil layer and maintaining oil phase permeability
3Ease of manufacture
If cyclohexane is used as continuous phase in polymer microsphere preparation, then polymerization can proceed, but the product has poor stability and low salt tolerance due to stratification
Solution Approach 1:
The patent replaces expensive and unstable cyclohexane with water as the continuous phase, using water-soluble crosslinking agents and surfactants to maintain polymerization processability while achieving superior stability and salt tolerance, effectively discarding the problematic cyclohexane system
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 solution provides a plugging agent with ultra-low interfacial tension and high salt tolerance, effectively addressing the limitations of existing agents by achieving high plugging and oil flooding rates with improved stability and applicability.
Implementation Method 1
10-25 wt % of a hydrophilic surfactant
Implementation Method 2
higher salt tolerance
Data Source
AI summary
A salt-tolerant polymer microsphere plugging agent and a preparation method thereof, the agent being made of white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, N,N′-methylene bisacrylamide, ammonium persulfate, sodium bisulfite, hydrophilic surfactant and water. The present general inventive concept synthesizes salt-tolerant polymer microspheres with ultra-low interfacial tension by adopting inverse phase emulsion polymerization. The prepared polymer microsphere plugging agent is a new type of polymer microspheres with ultra-low interfacial tension, such that the tension can reach 4.3×10−3 mN/m, and the salt tolerance can reach 50000 mg/L salinity, which improves the problem of low interfacial tension and poor salt tolerance in existing polymer microspheres.