Segmented Pressure Regulator for Polymer Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanical degradation of high molecular weight polymers used in enhanced oil recovery (EOR) processes is significant due to shear forces, especially when pressure reduction is required, leading to excessive viscosity loss and inefficiencies in current pressure regulation systems.
Innovation Solution
A pressure regulating device comprising a series of straight tubes separated by gate or needle valves, with intermediate pressure gauges, made of high-strength, corrosion-resistant materials, which allows for controlled pressure reduction to minimize polymer degradation, and a method to calculate and adjust the device's parameters for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a single pressure control valve (choke valve) is used at the wellhead to reduce injection pressure, then pressure regulation is achieved, but polymer degradation increases disproportionately
Solution Approach 1:
The single pressure control valve is segmented into multiple pressure control devices (first, second, and third pressure control devices) arranged in series. Each device reduces pressure by a controlled amount, preventing the disproportionate polymer degradation that occurs with single-stage pressure reduction. The segmentation allows gradual pressure decrease while maintaining polymer solution integrity.
Solution Approach 2:
The pressure control devices are made adjustable and controllable, allowing dynamic optimization of pressure reduction at each stage. This enables the system to adapt to varying flow rates and well conditions, maintaining optimal pressure differential across each device to minimize shear forces on the polymer while achieving the required pressure reduction.
2Quantity of substance
If high molecular weight polymers are used to achieve higher viscosities with low dosage, then EOR efficiency improves, but sensitivity to mechanical degradation increases
Solution Approach 1:
The polymer solution undergoes segmented pressure reduction through multiple control devices rather than a single abrupt pressure drop. This segmentation of the pressure reduction process minimizes shear forces at any given moment, protecting the high molecular weight polymer from mechanical degradation while maintaining the viscosity benefits of high molecular weight polymers.
Solution Approach 2:
The system changes the parameter of pressure differential across each control device, maintaining it within an optimal range (5-20 bars) to balance pressure reduction needs with polymer protection. This parameter optimization allows high molecular weight polymers to maintain their viscosity-enhancing properties without suffering excessive degradation.
3Adaptability or versatility
If pressure reduction is increased to accommodate heterogeneous field injection pressures, then adaptability to different wells improves, but polymer degradation becomes almost exponential
Solution Approach 1:
The system segments the total pressure reduction requirement into multiple smaller stages, each handled by a separate pressure control device. This allows the system to adapt to heterogeneous field conditions across different wells while preventing exponential polymer degradation through controlled, incremental pressure reduction at each stage.
Solution Approach 2:
Each pressure control device is made dynamically adjustable to accommodate varying well pressures and flow rates. This dynamic capability allows the system to adapt to heterogeneous field conditions while maintaining optimal pressure differentials that protect polymer integrity, even when total pressure reduction requirements vary significantly between wells.
4Ease of operation
If conventional choke valves are used for pressure control, then simple pressure regulation is achieved, but the pressure drop causes disproportionate polymer degradation
Solution Approach 1:
The conventional single choke valve is replaced with multiple pressure control devices arranged in series, each contributing to the overall pressure control function. This segmentation maintains ease of operation through individual valve control while distributing the pressure drop to minimize polymer degradation, overcoming the limitation of conventional single-stage pressure control.
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 achieves viscosity degradation of less than 10%, preferably less than 5%, by precisely regulating pressure drops across multiple valves and tubes, ensuring effective polymer injection with minimal mechanical degradation across varying well conditions.
Implementation Method 1
The polymers used, in particular polyacrylamides, undergo molecular weight degradation when subjected to a shear force
Implementation Method 2
which becomes almost exponential with increasing pressure
Data Source
AI summary
A pressure regulating device for the injection of an aqueous polymer solution into an oil well, the device consisting of a series of straight tubes each with a pressure gauge, each tube being separated by a valve, where the valves are gate valves and/or needle valves. A method to reduce the injection pressure of an aqueous polymer solution according to the pressure of the well using the device.