DIRECT MANUFACTURING METHOD FOR LARGE-SCALE, FRACTURED-CORE MODEL PRESERVING ORIGINAL OIL AND WATER SATURATIONS

摘要

Provided is a direct manufacturing method for a large-scale, fractured-core model preserving original oil and water saturations, the method comprising: (1) determining the volume (V), porosity, permeability (K), oil saturation (S_o) and water saturation (S_w) for the fractured core to be manufactured; (2) on the basis of the oil-/water-viscosity ratio of a reservoir, preparing simulation oil, and determining the mass of oil used by: m₀ = V₀ × ρ₀, where V₀ is oil volume in the core, and ρ₀ is oil density; (3) without considering oil saturations, obtaining the masses of water, cement, and quartz sand used as a, b, and c, respectively; (4) when establishing oil saturations, determining the mass of water used for manufacturing the core by: m_w = a-V₀ × ρ_w, where ρ_w is water density; (5) homogeneously mixing oil, water, and emulsifier to prepare an oil-in-water emulsion; (6) adding cement and quartz sand to the emulsion, mixing well, and obtaining a cement slurry; (7) when the cement sample is half-cured, wire cutting the cement sample in fracture directions according to experimental requirements; and (8) waiting until the cement sample is fully cured. The manufacturing method of the present invention has low production costs, is easy to execute, and can control fracture distribution in a core, thereby establishing a model and preserving saturations at the same time.