Numerical simulation method considering dynamic capillary force

Abstract

The invention discloses a numerical simulation method considering dynamic capillary force. The numerical simulation method comprises the steps that a plurality of test points are arranged on a rock core, dynamic capillary force curves of the test points under different displacement velocities are obtained through a dynamic capillary force test method; the function relationship among the dynamic capillary force, water saturation and the flow velocity is obtained by deducing through a percolation mechanics method, the dynamic capillary force curves obtained through experiment test are fitted by using the function relationship, and undetermined coefficients in the function relationship are obtained; a basic oil phase equation and a basic water phase equation are subjected to difference according to the function relationship, a difference discrete equation of the oil phase equation is obtained, and a difference discrete equation, relative to the dynamic capillary force, of the water phase equation is obtained; and the difference discrete equation of the oil phase equation and the difference discrete equation, relative to the dynamic capillary force, of the water phase equation are subjected to fully-implicit iterative solution, and a linearized coefficient matrix is obtained. The problem that in the prior art, the linearized coefficient matrix cannot be obtained is solved.

Description

technical field [0001] The invention relates to the application field of oil reservoir numerical simulation technology, in particular to a numerical simulation method considering dynamic capillary force. Background technique [0002] Capillary force is the abbreviation of capillary pressure, which refers to the pressure difference between two fluids (non-wet phase fluid and wet phase fluid) on both sides of the meniscus in the capillary. During the development of oil and gas reservoirs, the oil, water, and gas in the reservoir are always flowing, and the fluid flow will inevitably cause dynamic wetting hysteresis (the wetting angle changes caused by the fluid flow velocity being greater than the movement velocity of the three-phase boundary), thus A value that affects capillary forces during fluid flow. The capillary force involved in the process of seepage mechanics and reservoir numerical simulation should be a dynamic capillary force related to fluid flow velocity. Howe...

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Problems solved by technology

The above two models cannot be well used for numerical simulation calculations under reservoir conditions

Tian et al. introduced the dynamic capillary force into the basic seepage equation of reservoir numerical simulation, and used the finite difference method to solve it, but the solution method was the IMPES (explicit saturation, implicit pressure) method, which was stable and accurate. The accuracy is not as good as the fully implicit solution, and the calculation results are only compared with the laboratory experimental results, not with the actual production data

[0010] In the prior art, the way of not considering the dynamic capillary force in the reservoir numerical simulation affects the accuracy of the simulation results

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