Deep oil reservoir high-temperature and high-pressure gas-displacing oil microcosmic visualization experiment method

Abstract

The invention discloses a deep oil reservoir high-temperature and high-pressure gas-displacing oil microcosmic visualization experiment method, which comprises the following steps of: installing a glass etching model for simulating a rock sample under an actual reservoir condition in a high-pressure sealed holder, and performing vacuumizing; injecting confining pressure liquid into a reservoir confining pressure annular cavity, and controlling the confining pressure through a confining pressure tracking pump; heating the confining pressure liquid in the reservoir confining pressure annular cavity through a high-temperature heating container; placing a glass etching model under a microscope; loading crude oil and a displacement fluid medium into a heating constant-temperature piston container, and adjusting a back pressure unit to a stratum simulation pressure; and carrying out a water and gas injection displacement experiment through a high-pressure injection pump and a gas pressurization system. The method can be used for simulating the oil-water-gas distribution state and fluid migration characteristics in a micro-nano pore structure, quantitatively characterizes the high-temperature and high-pressure water drive, gas drive and chemical drive microcosmic remaining oil starting mechanism, and has important guiding significance for judging the oil-water saturation distribution and size in the oil field reservoir development process.

Description

technical field [0001] The invention relates to the technical field of microscopic displacement, in particular to a microscopic visualization experiment method for high-temperature and high-pressure gas flooding in deep oil reservoirs. Background technique [0002] With more and more exploration and development activities in deeper and more complex formations around the world, it is becoming more and more difficult to tap the remaining oil potential under high temperature and high pressure conditions in deep formations. Especially when the oilfield enters the period of production decline in the high water-cut development stage, the mining potential target is gradually shifting from the large connected remaining oil to the highly dispersed, localized and relatively enriched areas. Due to unclear understanding of the microcosmic occurrence and distribution of remaining oil, Seriously hindered the remaining oil potential in the next step. Therefore, it is particularly importan...

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Problems solved by technology

However, this technology has great limitations. On the one hand, the rock will be worn during use, and the basic parameters of the rock will change with the experimental process, and the used rock is not easy to wash, and the repeatability is low; in addition, conventional microscopic flooding There are two main problems in the replacement experimental device. One is that due to the deep burial of complex oil reservoirs, high temperature and high pressure (70MPa, 150°C), it is difficult for conventional experimental devices to reproduce the high temperature and high pressure conditions of real reservoirs; on the other hand, Due to the small pore size, it is difficult for conventional experimental devices to intuitively display the migration laws of fluids with different properties in micro-nano-scale channels, and to conduct qualitative and quantitative analysis of the remaining oil distribution laws

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