Shear-Responsive Supramolecular Preformed Particle Gel: Tailoring Network Architectures for Selective Water Blocking.

Area of Science:

• Petroleum Engineering
• Polymer Science
• Materials Science

Background:

• Excessive water production in oil fields increases costs and reduces hydrocarbon recovery.
• Conventional hydrogels, like preformed particle gels (PPGs), have limited effectiveness at high flow rates and harsh reservoir conditions.
• Improving water-blocking treatments is crucial for efficient oil and gas extraction.

Purpose of the Study:

• To enhance the shear-responsive mechanical properties of preformed particle gels (PPGs) for effective water blockage in challenging oil reservoirs.
• To investigate methods for improving PPG performance at high flow rates and under harsh environmental conditions.
• To develop a novel approach for tailoring PPGs for selective and robust water control.

Main Methods:

• Modified composite PPGs by increasing intermolecular interactions through cationic group incorporation and secondary interpenetrating network formation.
• Utilized molecular simulations to interpret experimental observations of shear-thickening and permeability reduction.
• Conducted laboratory tests to evaluate water residual resistance factor and disproportionate permeability reduction.

Main Results:

• Developed PPGs exhibiting shear-thickening behavior (n > 1), deviating from conventional shear-thinning.
• Achieved significant Disproportionate Permeability Reduction (from 8 to 117) in high-flow-rate zones, preferentially reducing water flow over oil.
• Demonstrated enhanced strength, thermal stability, and resistance to washout under high-pressure gradients.

Conclusions:

• Tailoring the microscopic architecture of PPGs can significantly improve their effectiveness in water-blocking treatments.
• The enhanced PPGs offer a high-efficiency solution for managing water production in complex and harsh reservoir environments.
• This research presents a novel strategy for robust and selective water control in the oil and gas industry.