Method for simulating flow of supercritical CO2 in displacement of natural gas with supercritical CO2

Abstract

The invention provides a method for simulating the flow of supercritical CO2 in displacement of natural gas with the supercritical CO2. The method comprises the following steps that: a three-dimensional geological model is established according to the geological characteristics of a gas reservoir; a fluid model is established through an improved state equation, so that the basic parameters of thefluid of the gas reservoir are determined; the diffusion coefficient of the CO2 is determined; the multi-component numerical simulation model of the displacement of the natural gas with the supercritical CO2, which considers diffusion, is established; and corresponding relations between different CO2 flooding quantities and natural gas production quantities are calculated through using the model.The present invention provides the new mathematical model and processing method to simulate the flow characteristics of the supercritical CO2 in the displacement of the natural gas with the supercritical CO2. Compared with a conventional numerical model, the model can better evaluate the flow characteristic of the CO2 in the displacement of the natural gas and the displacement effect of the CO2.

Description

technical field [0001] The invention belongs to the field of gas reservoir development, and in particular relates to a simulated supercritical CO 2 A method of displacing natural gas flows. Background technique [0002] Due to the excessive dependence of human beings on fossil fuels (coal, oil, natural gas), the amount of greenhouse gas emissions produced by industry and human life is increasing day by day. The resulting air pollution and greenhouse effect are seriously threatening the survival of human beings. environment. The greenhouse gas carbon dioxide (CO 2 ) warms the global climate and poses a serious threat to human survival and social and economic development. CO 2 Effective utilization has become a topic of widespread concern around the world. Through continuous development and improvement, injecting CO into the reservoir 2 become a more mature technology. [0003] But injecting CO into the gas reservoir 2 The phase state and displacement mechanism are com...

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Problems solved by technology

[0005] In order to solve the deficiencies of the prior art, the present invention explores and proposes a volume-improved equation of state method to solve the problem of high CO content at low temperatures. 2 The problem of difficult fitting of gas experiment data; and the consideration of CO under different pressure conditions 2 Effect of Diffusion on Displacing Natural Gas, Establishing a Supercritical CO with Diffusion Considered 2 Multi-component numerical simulation model for flooding natural gas, simulating supercritical CO 2 Natural gas displacement mechanism and displacement effect

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