A two-dimensional visual seepage experimental method for simulating intralayer heterogeneity

Abstract

The invention discloses a two-dimensional visual percolation experiment method capable of simulating in-layer heterogeneity. The method comprises the following steps: filling sandstone core particles with different sizes into a two-dimensional visual sand-filled model for simulating the in-layer heterogeneity, flattening and pressing the filled particles; applying a pressure on a confining pressure cavity through a pressurizing opening; saturating the permeation layer by simulated stratum water, measuring the permeability of the permeation layer to obtain the average permeability of the two-dimensional visual sand-filled model; saturating the permeation layer by simulated stratum oil; according to the target oil reservoir, determining the shearing speed of an oil displacing system in the permeation layer, calculating the injection amount of the oil displacing system according to a formula (a); arranging a high-resolution camera above the two-dimensional visual sand-filled model; using the high-resolution camera to collect the images, obtaining the change of the oil saturation of the permeation layer through the change of the color step values of the collected images, and finally recording the change situation of displacing front of the oil displacing system. The provided experiment method can visually and dynamically observe the percolation change rules of an oil displacing system in a sand-filled model and precisely represent the waves and efficiency differences of different oil displacing system.

Description

technical field [0001] The invention relates to a two-dimensional visible seepage experimental method for simulating intralayer heterogeneity. Background technique [0002] The core of reservoir research is reservoir heterogeneity. Reservoir heterogeneity research is an important basic work in the geological research of oil and gas field exploration and development. At present, many oil fields in China have entered the medium-high water cut period and production reduction period, and this research is particularly important. Reservoir heterogeneity reduces the sweep coefficient of water flooding or chemical flooding, resulting in lower ultimate recovery and resulting in ineffective circulation of water injection or injection agents. Therefore, understanding the oil displacement efficiency and seepage law of water flooding or chemical flooding in heterogeneous reservoirs provides a theoretical basis for the development, evaluation, screening and further improvement of oil rec...

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Problems solved by technology

The above models and experimental methods cannot visually and dynamically observe the seepage change of the oil displacement system in the heterogeneous porous media in the layer, and they all simulate the point-to-point injection-production relationship of the oilfield well pattern with combined injection and production, and combined injection and separate production. After long-term water injection development, the near-wellbore area contains less oil, and the remaining oil is mainly distributed in deep reservoirs and areas with prominent heterogeneity. Therefore, it is necessary to develop an experimental method for simulating the seepage of oil displacement systems in deep formations.

In addition, in the actual production process of the oil field, as the oil displacement system enters the deep part of the reservoir, the affected area becomes wider and wider, the flow velocity becomes slower and slower, and the shear rate of the fluid is constantly changing. The key to the sweep efficiency of the flooding system, the point-to-point injection-production relationship cannot reflect the seepage law of the flow rate change of the flooding system in actual oilfield development

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