An oil–water two-phase reservoir numerical simulation coupled with dynamic capillary force based on the full-implicit method

Wang, Shuoliang; Yu, Cheng; Sang, Guoqiang; Yu, Rong; Cheng, Feng

doi:10.1016/j.camwa.2019.11.013

Cited by 4 publications

(4 citation statements)

References 22 publications

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“…In this section, we present the mathematical model describing this flow characteristic in tight, porous media. Based on the oil–water two-phase porous flow model, the assumptions are as follows: There are exactly two phases (water, oil) in fractured tight oil reservoir. Volume fracturing is conducted with a water-based fracturing fluid and treated with a water phase. The fracture with a vertical form runs through the whole thin layer, ignoring the effect of gravity. Fluid flow is regarded as a Darcy flow characteristic. There is no mass exchange between oil and water phases. Instantaneous phase equilibrium is observed during this porous flow. The whole process is isothermal. …”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Cai developed a generalized spontaneous imbibition model which considers the different sizes and shapes of pores; the generalized model can be used to characterize the spontaneous imbibition behavior of many different porous media and that pore shape cannot always be assumed to be cylindrical . Wang established a numerical simulation method coupled with the dynamic capillary force and explained the difference between reservoir numerical simulation with static and dynamic capillary pressure in two-dimensional homogeneous and heterogeneous models . In terms of analytical solution or semianalytic solution, some scholars have also achieved results.…”

Section: Introductionmentioning

confidence: 99%

“… 25 Wang established a numerical simulation method coupled with the dynamic capillary force and explained the difference between reservoir numerical simulation with static and dynamic capillary pressure in two-dimensional homogeneous and heterogeneous models. 26 In terms of analytical solution or semianalytic solution, some scholars have also achieved results. An analytical solution for cocurrent and counter-current spontaneous imbibition has been derived in a way similar to the Buckley–Leverett theory, Schmid and Alyafei compared their solution with measured saturation profiles.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Mathematical Model of Imbibition Replacement and Optimization of Soaking Time for Massively Fractured Tight Oil Reservoirs

Liu,

Zhu,

Liao

et al. 2023

ACS Omega

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Due to the small pore throat characteristics of tight oil reservoirs, their strong capillary pressure makes imbibition replacement an effective development method. Field data has indicated that only a little fracture fluid can flow back and that there is an enhancement in oil recovery with shut-in periods after volume fracturing. A large number of scholars have carried out core-scale experiments on imbibition characteristics, but there has been limited research on the quantitative characterization of the differential pressure and imbibition replacement during counter-current imbibition. At the same time, there was also controversy on the calculation method of the optimal soaking time. In this paper, a mathematical model of oil–water two-phase flow is first established. Then, a mathematical model representing differential pressure and imbibition replacement in tight reservoirs is derived with a diversion function. Based on the saturation equation, Corey relative–permeability curve, and J function, the model is simplified to a mathematical model of spontaneous imbibition in the shut-in periods after volume fracturing. Second, based on the finite difference method, a dynamic solution method for the flow field considering the dynamic capillary force was established, and the variation law of the pressure field and the water saturation field during the soaking time was revealed. The simulation results show that imbibition characteristics are the core of flow field reconstruction, and the differential pressure action can ensure the advancing distance of the fracturing fluid; both of them are not a linear superposition on tight oil development but complement each other and promote each other. Third, according to the growth rate of the imbibition replacement between fractures and the matrix during the soaking time, the calculation method of optimal soaking time was established. Taking the development parameters of the volume fracturing development case in the Ordos Basin into account, a reasonable soaking time was optimized. Finally, we analyzed the optimal soaking time under different conditions, and a chart of optimal soaking time for different initializations was plotted. Such a chart has profound reference significance for engineers, and they can make quick and accurate decisions regarding development and adjustment.

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