Experimental Study On Oil - Water Seepage Curve Of Fractured Reservoir

For now, with the increasing of world oil demand, fractured reservoirs which accounting for almost half of the proven reserves have started suffering valuing. Compared with the porosity reservoirs fractured reservoirs are more anisotropic and the rule of oil-water movement is complex. It’s relative permeability is affected by many factors such as physical properties of rocks, fracture network model, wetting property, viscosity ratio of oil and water, displacing velocity and pressure. So it’s relative permeability data acquisition is relatively difficult. Therefore, further study of relative permeability curve of fractured reservoir factors and calculation method is of great significance.This paper focuses on the research of relative permeability curve calculation model of fractured carbonate reservoir. Based on the investigation of the ways that how to gain the relative permeability curve and the indoor physical simulation method of fractured reservoir. On the basis of the geological causes of crack network and oil field geological data consider similar we have designed and made up the visual models and full diameter core models. We have carried out many water oil displacement experiments. Finally this paper put forward the calculation method of relative permeability curve for fractured reservoir. The main research results are as follows:1) Designed and made up the visual models and full diameter core models and the corresponding experiment schemes.Based on the field geological data and the similarity principle especially Network mode and the fracture width, we made up two visual models (heterotropic network and complex network)and two full diameter core models(parallel network and heterotropic network). To research viscosity ratio ofoil and water, displacing velocity and Network mode and other factors’impact on relative permeability.2) A series of visual model experiments have performed.This part of experiment highlighted the viscosity ratio of oil and water and network mode’s affection on relative permeability. Based on the results of experiment expounded water flooding characteristic and the distribution of remaining oil.3) A series of full diameter core model experiments have performed.As a supplement to visual model experiments this part of experiments are operated at high temperature and high pressure. This part of experiment highlighted displacing velocity’s affection on relative permeability. Analysis suggested that moderate displacing velocity is best to the increase of oil recovery. The best displacing velocity is obviously related to the viscosity ratio of oil and water and network mode.4) Two calculation methods of relative permeability have obtained, one from experimental data matching the other one from theoretical inference.By matching the experimental data of visual mode experiments the calculation method which considered viscosity ratio of oil and water and network mode have obtained. By theoretical inference another calculation method which considered fracture width distribution have obtained. This research suggested that if fracture width follow Gaussian distributions N(μ,(?)2) the larger the number of μ, the more right the relative permeability curve is. the larger the number of (?)2, the more left the relative permeability curve is.