Functionalized Silicone Polymer Viscosity Control for Supercritical CO2
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Solution Overview
Problem
The low viscosity of supercritical carbon dioxide hinders its effectiveness in enhanced oil recovery (EOR) and hydraulic fracturing processes, leading to inefficient oil and gas extraction, as it tends to 'finger' through formations rather than effectively sweeping oil, and requires large volumes of water, which introduces operational difficulties and environmental concerns.
Innovation Solution
A functionalized silicone polymer with anthraquinone amide, sulfonamide, thioxanthone amide, or thioxanthone sulfone amide groups is used to increase the viscosity of supercritical CO2 and hydrocarbon solvents, allowing for improved solvent mobility and reduced water usage in EOR and fracturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If supercritical CO2 is used as a flooding agent in EOR, then environmental sustainability and oil solubility are improved, but viscosity remains too low causing CO2 to finger through petroleum and bypass most oil
Solution Approach 1:
The patent changes the chemical composition parameters of supercritical CO2 by dissolving organic compounds (such as alkanes, cycloalkanes, or aromatic hydrocarbons) into it. This parameter change increases the viscosity of CO2 from its naturally low state to a level sufficient for effective oil recovery, while maintaining its environmental benefits and oil solubility properties.
Solution Approach 2:
The patent creates a composite fluid system by combining supercritical CO2 with organic thickening agents. This composite material exhibits both the environmental sustainability and oil solubility of CO2 plus the enhanced viscosity needed for effective flooding, resolving the contradiction between low viscosity and environmental benefits.
2Productivity
If large volumes of supercritical CO2 are injected to compensate for low viscosity, then oil recovery is attempted, but the process requires very large amounts of purchased and recycled CO2 over extended periods
Solution Approach 1:
By changing the viscosity parameter of CO2 through the addition of organic compounds, the patent enables effective oil recovery with significantly reduced CO2 volumes. The thickened CO2 achieves better sweep efficiency, reducing the need to inject very large amounts of CO2 over extended periods.
3Force
If WAG process (alternate injection of water and supercritical CO2) is used, then CO2 mobility is decreased and recovery becomes more economical, but operational difficulties increase due to producing, separating, processing, and re-injecting large volumes of water
Solution Approach 1:
The patent extracts water from the EOR process by using organic compounds that are soluble in supercritical CO2 as thickening agents. This eliminates the need for the WAG process's water injection and handling steps, simplifying operations while maintaining CO2 mobility control through viscosity modification.
Solution Approach 2:
The patent uses small amounts of organic compounds as disposable thickening agents dissolved in CO2, replacing the complex water handling infrastructure required by WAG processes. This reduces operational complexity while achieving the desired mobility control.
4Force
If high-molecular weight organic polymers such as copolymers of styrene and fluorinated acrylates are used to thicken supercritical CO2, then viscosity is increased, but the materials can be very expensive and toxic
Solution Approach 1:
The patent replaces expensive, potentially toxic high-molecular-weight polymers with simpler, cheaper organic compounds (alkanes, cycloalkanes, or aromatic hydrocarbons) that serve as effective thickening agents. These simpler compounds reduce both cost and toxicity concerns while achieving the desired viscosity increase.
Solution Approach 2:
The patent changes the molecular weight parameter of the thickening agent from high (polymers) to low (simple organic compounds). This parameter change maintains the ability to increase CO2 viscosity while eliminating the cost and toxicity issues associated with high-molecular-weight materials.
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 modified silicone polymer significantly increases the viscosity of supercritical CO2 and hydrocarbon solvents, enhancing oil recovery by improving solvent sweep efficiency and reducing the need for large water volumes, thus optimizing extraction processes and minimizing environmental impact.
Implementation Method 1
A thickening agent for organic liquid compositions or supercritical fluids, or mixtures thereof, is also an embodiment of this invention. The thickening agent is a silicone polymer that contains at least one functional group selected from anthraquinone amide groups; anthraquinone sulfonamide groups; thioxanthone amide groups; or thioxanthone sulfone amide groups.
Data Source
AI summary
A silicone polymer is provided, modified with at least one functional group from the class of anthraquinone amide groups; anthraquinone sulfonamide groups; thioxanthone amide groups; or thioxanthone sulfone amide groups. The polymer can be combined with a hydrocarbon solvent or with supercritical carbon dioxide (CO2), and is very effective for increasing the viscosity of either medium. A process for the recovery of oil from a subterranean, oil-bearing formation is also described, using supercritical carbon dioxide modified with the functionalized silicone polymer. A process for extracting natural gas or oil from a bedrock-shale formation is also described, again using the modified silicone polymer.