Imbibition oil recovery of single fracture-controlled matrix unit: Model construction and numerical simulation

Abstract

The fracture-controlled matrix unit is commonly found in low-permeability fractured reservoirs. Due to the permeability difference between the fracture system and the matrix system, a large amount of oil will remain in the matrix during traditional water injection development, thus limiting reservoir productivity. However, the special imbibition mode of the fracture-controlled matrix unit provides a breakthrough for secondary oil recovery. In this paper, based on the model of single fracture-controlled matrix unit, the dynamic production process of fractured reservoir is studied by the numerical simulation method. The numerical simulation of the imbibition oil production is carried out on the two-point well model by using the method of huff and puff injection. The results show that imbibition is the main mechanism in the middle and late stages of oil recovery from fractured reservoirs. The water in the fracture is absorbed into the matrix by capillary force and the oil is replaced; in this way, imbibition can increase the recovery rate by 20%. The findings provide a basis for the further study of the fracture-controlled matrix unit and imbibition. Cited as: Liu, Q., Liang, B., Liu, J., Sun, W., Lei, Y. Imbibition oil recovery of single fracture-controlled matrix unit: Model construction and numerical simulation. Capillarity, 2022, 5(2): 32-40. https://doi.org/10.46690/capi.2022.02.02