Numerical Simulation of Low-Permeability Fractured Reservoirs on Imbibition

Abstract

Low permeability fractured reservoir is a special reservoir with complex fracture distribution and dense matrix. Low permeability fractured reservoir always have small porosity, low pore pressure and permeability. Therefore, low permeability fractured reservoir has low oil recovery efficiency. Besides, the developing complex process and higher costs lead to lower economic benefit. Low permeability fractured reservoir production mechanisms in the fracture system mainly by the capillary force of water into the matrix. Therefore, the hydrophilic blocks of dense, self-priming effect of capillary water is the main mechanism of oil. In this study, numerical simulation, the establishment of a dual media model analysis showed that the capillary suction from the oil production rate and the final volume flow channel structure, the capillary force, viscosity of crude oil and other factors.

Pore-scale numerical simulation of spontaneous imbibition in porous media containing fractures

“…Fractured reservoirs, such as shale and tight sandstone, constitute a significant portion of remaining oil reserves; they are widely distributed around the world and have the characteristics of low permeability, low porosity and thus present several production challenges. Large-scale volumetric fracturing can realize the economic exploitation of lowpermeability reservoirs (Wu et al, 2013). Driven by capillary force, the water-based fracturing fluid in the hydraulic fracture system is spontaneously imbibed into the matrix system and displaces the oil in the matrix pores.…”

Numerical Simulation of Microemulsion Flooding in Low-Permeability Reservoir

“…With the characteristics of narrow pores, large pore-throat ratio, high irreducible water saturation, and serious heterogeneity, the low-permeability reservoirs do not meet Darcy's law anymore and there is threshold pressure gradient. Compared to the high-pressure of water injection, low water displacement efficiency, and low ultimate recovery efficiency of water flooding [1][2][3][4], the surfactant flooding can reduce the threshold pressure gradient and injection pressure, increase the water injection rate which expands the swept volume, reduce the interfacial tension, and improve the displacement efficiency [5][6][7][8]. According to the surfactant concentration in the injection system, the surfactant flooding is divided into active water system (C s < 1%) and microemulsion system (C s � 3%∼5%) [9][10][11][12][13].…”