Development and Performance Evaluation of a New Conformance Control Agent Gel

Area of Science:

• Petroleum Engineering
• Materials Science
• Polymer Chemistry

Background:

• Efficient water flooding in fractured low-permeability oil reservoirs is hindered by multi-scale fractured water channeling.
• Effective plugging of these channels is crucial for optimizing oil recovery.

Purpose of the Study:

• To develop a new supramolecular-polymer composite gel for plugging multi-scale fractured water channeling.
• To evaluate the gel's performance as a conformance control agent in fractured low-permeability oilfields.

Main Methods:

• Formulation of a composite gel using polyacrylamide, polyethyleneimine, cyclodextrin, and ethyl alcohol.
• Characterization of the gelant's initial viscosity and injection performance in micro-fractures.
• Analysis of the gel's double network structure formation at 40°C via covalent and self-assembly interactions.

Main Results:

• The composite gelant exhibits low initial viscosity (<20 mPa·s) for effective injection into micro-fractures.
• Upon gelation at 40°C, a stable double network structure is formed.
• The resulting composite gel shows significantly enhanced strength (>5 × 10^4 mPa·s) and effective plugging in large-scale fractures.

Conclusions:

• The developed supramolecular-polymer composite gel is a promising solution for plugging multi-scale fractured water channeling.
• Its dual-network structure provides superior plugging performance in fractured low-permeability reservoirs.
• The gel serves as an effective conformance control agent, improving water flooding efficiency.