Intrinsic Viscosity Determination for Acrylamide Polymer Solutions
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Solution Overview
Problem
Current methods for determining the viscosity of acrylamide-based polymer solutions in various conditions are complex, time-consuming, and costly, and do not accurately measure molecular weight without lengthy measurements.
Innovation Solution
A method using universal relations to calculate intrinsic viscosity based on specific viscosity at zero shear rate and polymer concentration, allowing for easy and rapid determination of viscosity and molecular weight through limited measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional methods are used to determine viscosity of polymer solutions, then measurement accuracy can be maintained, but the procedure becomes complex, time-consuming and costly
Solution Approach 1:
The invention changes the measurement parameters by using specific viscosity at zero shear rate (ηsp(0)) and polymer concentration (C) as input parameters, and applies mathematical transformations through universal relations to obtain intrinsic viscosity. This parameter transformation approach simplifies the measurement procedure while maintaining accuracy across different conditions including varying salinity and temperature.
Solution Approach 2:
The invention establishes universal relations that are applicable across multiple conditions (different salinities from 6-250 g/L, different temperatures, different polymer concentrations). A single set of universal relations can determine intrinsic viscosity for various acrylamide-based polymers under diverse EOR conditions, eliminating the need for separate calibration curves for each condition and significantly reducing measurement complexity.
2Measurement precision
If traditional methods are used to determine viscosity, then comprehensive data can be obtained, but the procedure becomes time-consuming
Solution Approach 1:
The invention performs preliminary action by establishing universal relations beforehand that capture the relationship between specific viscosity, polymer concentration, and intrinsic viscosity across multiple conditions. Once these universal relations are established, determining intrinsic viscosity for new polymer solutions becomes a rapid calculation based on simple measurements of specific viscosity and concentration, eliminating the need for time-consuming step-by-step experimental procedures for each new sample.
3Measurement precision
If traditional methods are used to estimate viscosity under different conditions, then accuracy can be maintained, but the procedure becomes costly
Solution Approach 1:
The universal relations serve multiple functions: they work for different polymer concentrations, different salinities (6-250 g/L), different temperatures, and various acrylamide-based polymers. This multi-functionality eliminates the need for separate expensive measurements and calibrations for each condition, reducing overall measurement costs while maintaining accuracy across the full range of EOR conditions.
4Adaptability or versatility
If polymer concentration and molecular weight are varied to study viscosity, then comprehensive characterization can be achieved, but the number of measurements increases
Solution Approach 1:
The invention transforms the characterization approach by using the relationship between specific viscosity, polymer concentration, and intrinsic viscosity as the basis for analysis. By measuring only specific viscosity and concentration, and applying the universal relation, one can determine intrinsic viscosity which then serves as a basis for characterizing polymer properties including molecular weight effects, eliminating the need for numerous separate measurements at each concentration level.
Data Source
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AI summary
The invention relates to a method for determining the intrinsic viscosity [η] of an aqueous polymer solution at a temperature T, wherein the aqueous polymer solution comprises at least one acrylamide-based polymer in an aqueous solvent, the aqueous solvent having a salinity of from6 to 250 g/L, the method comprising the steps of: –providing a single universal relation R1 between (i), the product of polymer concentration and intrinsic viscosity C·[η], and (ii) specific viscosity at zero shear rate ηsp; –performing a measurement of the dynamic viscosity of the aqueous polymer solution at one polymer concentration C1, at temperature T and at various shear rates; –determining from said measurement the zero-shear viscosity η0 of the aqueous polymer solution at polymer concentration C1 and at temperature T; –calculating the specific viscosity at zero shear rate of the aqueous polymer solution at polymer concentration C and at temperature T as ηsp =(η0 -ηs) / ηs, where ηs is the zero-shear viscosity of the aqueous solvent; –estimating the intrinsic viscosity [η] of the aqueous polymer solution at temperature T by applying the universal relation R1 to the calculated specific viscosityat zero shear rate ηsp and polymer concentration C1.