Carbon dioxide imbibition diffusion oil discharge experimental device in tight oil reservoir

Abstract

The invention discloses a carbon dioxide imbibition diffusion oil discharge experimental device in a tight oil reservoir. The experimental device comprises a multi-stage rock core holder, a crude oilinjection device, a recovery device, an intermediate container, a high-pressure gas cylinder, an injection pump, a confining pressure pump, a back pressure pump, a collection device and a control system, a connecting hole is formed between the top and the bottom of the multi-stage rock core holder, an oil injection pipe is arranged between the connecting holes in the top and the bottom, and the crude oil injection device and the recovery device are connected to the top and the bottom of the oil injection pipe; a plurality of rows of small holes are formed in the side surface of the multi-stagerock core holder and serve as a gas inlet and a gas outlet; the gas inlet is connected to the intermediate container through a pipeline, the intermediate container is connected to the high-pressure gas cylinder and the injection pump, and the gas outlet is connected to the collecting device; the multi-stage rock core holder is also connected with a confining pressure pump; and heating layers arearranged on the inner walls of the multi-stage rock core holder and the intermediate container. Through further improvement of an existing experimental device, authenticity simulation of complex wellconditions can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to an experimental device, in particular to an experimental device for carbon dioxide imbibition, diffusion and oil discharge in tight oil reservoirs. Background technique [0002] With the development of unconventional oil and gas fields in my country, tight oil and gas resources have become the key research object of domestic oil development. Due to the low porosity and low permeability of tight oil reservoirs, conventional water injection cannot effectively replenish the formation capacity, and many tight oil production areas in China happen to be water-scarce areas, making it difficult to provide large amounts of water. Therefore, how to effectively improve the recovery of tight oil reservoirs has become a key problem that needs to be solved urgently. Since carbon dioxide is a gas with high solubility in oil and water, when it dissolves in crude oil in lar...

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Problems solved by technology

[0003] Due to the high cost of on-site experiments in the petroleum industry, most experiments need to be pre-researched through computer simulation and experimental devices. At present, there is no special device for the dialysis and oil drainage experiments of carbon dioxide in tight oil reservoirs. The application number is The Chinese patent of 201910069483.3 provides an experimental device that can be used as a carbon dioxide dialysis oil drainage experiment, but its structure is suitable for single-layer oil wells. In reality, most perforations are layered perforations, providing multi-layer fracturing fractures. Its crude oil dialysis pattern is more complex

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