Preparation and Experimental Study of a Low-Initial-Viscosity Gel Plugging Agent
Bin Huang1,2, Weisen Zhang1, Quan Zhou3
1Key Laboratory of Enhanced Oil Recovery (Northeast Petroleum University), Ministry of Education; College of Petroleum Engineering, Northeast Petroleum University, Daqing 163318, China.
ACS Omega
|July 9, 2020
Summary
A new low-initial-viscosity gel plugging agent effectively addresses seepage channels in polymer flooding. This optimized gel enhances oil recovery by over 13.6% and shows excellent plugging performance in field tests.
Area of Science:
- Petroleum Engineering
- Enhanced Oil Recovery
- Materials Science
Background:
- Polymer flooding can lead to dominant seepage channels, hindering effective reservoir exploitation.
- Conventional gel plugging agents often have high initial viscosity, causing issues in medium- and low-permeability formations.
Purpose of the Study:
- To develop a novel low-initial-viscosity gel plugging agent for improved reservoir management.
- To optimize gel formulation for effective plugging and enhanced oil recovery.
Main Methods:
- Formulation optimization of polymer, cross-linking agent, and functional auxiliaries.
- Core plugging performance tests and three-tube core parallel oil displacement experiments were conducted.
Main Results:
- The optimal gel formulation includes specific concentrations of polymer LH2500, cross-linking agent CYJL, citric acid, sodium sulfite, and sodium polyphosphate.
- The developed gel exhibits initial viscosity < 10 mPa·s, controllable gelation time (10-40 days), and high gelation viscosity (> 2000 mPa·s).
- Achieved >99% water plugging rate in cores (0.48-3.9 μm²) and increased recovery factor by 13.6% in secondary polymer flooding reservoirs.
Conclusions:
- The low-initial-viscosity gel plugging agent demonstrates superior performance in plugging seepage channels and enhancing oil recovery.
- Successful field applications confirm its effectiveness for oil increase and water control in mature reservoirs.
