Two-Dimensional Visual Analysis of Three-Phase Foam Flooding under Different Reservoir Conditions

Abstract

In the later stage of water flooding, the water cut of the reservoir is high and the water channeling of the interlayer is severe, leading to the invalid or inefficient circulation of injected water and to poor development results. However, the three-phase foam (TPF), which combines the advantages of foam and particles, is strongly applicable for high water cut reservoirs. To explore the plugging and profile control mechanisms of the TPF and the degree of improving oil recovery, branched-formed particle gel (B-PPG), surfactant DLY-05, and N2 were mixed to form the TPF. The system was used in two-dimensional flooding experiments consisting of homogeneous, positive rhythm, reverse rhythm, and high-permeability channel models. Quantitative and qualitative analyses were carried out with the displacement phenomenon and the dynamic parameters of oil production. Such a water cut, production pressure difference, and recovery factor were analyzed in detail. The results show that the TPF has good adaptability to four high water cut models. When TPF is injected, the water cut of the produced liquid is significantly reduced, and the production pressure difference and oil recovery factor are significantly increased. The decrease in water cut ranges from 17.26 to 22.27%, corresponding to an increase in the oil recovery factor of 20.63 to 28.28%. The dynamic changes in the model flow line and flow field in different flooding stages show that the TPF can control the profile and flooding oil. In addition, when flexible particles deform and enter the small pore throat, residual oil is squeezed and carried out. The research results provide a theoretical reference for the application of a three-phase foam in actual reservoirs. The study of TPF in a high water cut reservoir provides a reference for its application in an actual reservoir in the future.

Micro and Macro Flooding Mechanism and Law of a Gel Particle System in Strong Heterogeneous Reservoirs

“…Inorganic particles are less affected by temperature and salinity but are poor in selective plugging, and raw materials are greatly affected by the origin [16][17][18]. Foams have strong selective plugging abilities which enables them achieve high-temperature and high-salt resistance, but they have short validity periods and involve complex construction technology [19][20][21][22]. Resin has a high plugging strength and a long validity period but poor selective plugging and is difficult to remove after plugging [23][24][25].…”