Research on heterogeneous compound flooding system based on dispersed particle gel

Aiming at the problem that the heterogeneity of the reservoir became strong, the remaining oil distributed universally after polymer flooding and the existing chemical compound flooding systems had limited application, a heterogeneous compound flooding system based on gel dispersion particles (DPG) was proposed as a substitution technology for further enhanced recovery of reservoirs after polymer flooding. This paper has carried out the design and characterization of heterogeneous compound flooding system, influencing factors, and application performance. With the system viscosity and oil-water interfacial tension as evaluation indicators, the application performance of the optimized heterogeneous polymer flooding system based on DPG was examined. The results showed that the system viscosity was 12.1 to 17.3 mPa•s while the interfacial tension was maintained at 10 -3 mN/m magnitude. At 80 °C, with 60 days aging, the viscosity retention ratio of the system is over 83.5%, and the interfacial tension between oil and water was still maintained at 10 -3 mN/m. The core flow experiment shows that, the heterogeneous compound flooding system has good injection performance, moving characteristics of plugging, breakthrough migration and re-plugging. After high-temperature aging, subsequent water flooding still maintained at a high pressure with good resistance to erosion. Through the selective high and low permeability layers, the water absorption profile was improved, and finally enhanced oil recovery to 20.61% after polymer flooding. Cited as : Li, H., Wang, K., Han, X., Zheng, J. Research on heterogeneous compound flooding system based on dispersed particle gel. Advances in Geo-Energy Research, 2019, 3(2): 156-164, doi: 10.26804/ager.2019.02.05.