Veservoir Adaptability and Fluid Diversion Effect of PPG Dispersion Systems

Performed particle gels (PPG) are prepared from monomers such as acrylamide, and have the advantages of temperature resistance, salt resistance, and controllable particle sizes. The matching degree between PPG particle sizes and the reservoir throat size significantly impacts the fluid diversion effect. Here, the particle size, micromorphology, dispersed system viscosity, Zeta potential, expansibility and stability of PPGs were analyzed using instrument detection and indoor physical simulation. The core permeability limit was determined through fluidity experiments, and the fluid diversion effect of PPGs was analyzed from parallel core experiments. Dry PPG powder particles were irregularly shaped, and PPGI and PPG II had initial particle sizes of 296.5 and 805.3 μm respectively and can expand in water. They expanded to the maximum particle size in about 24 h, and the expansion ratio was between 1.07 and 1.14. At the concentration of 0.1%, the viscosity of the PPG I and PPG II dispersion systems was 2.98 and 8.47 mPa·s, respectively. PPGs were negatively charged in water and remained stable for 60 days. The PPG injection condition was the matching factor Ra > 0.032. When the permeability difference was 5.35 and after injection of a PPG dispersion system, the diversion rate of the low-permeability layers was >50%, showing a good fluid diversion effect. The optimal matching factor range between PPG particle size and core pores was determined through resistance factor detection experiments, which provides a decision-making basis for on-site application of heterogeneous profile control systems.