化学反应及相间传质对CO2/水/烷烃三相流体在多孔介质孔隙内流动的影响规律研究

The research on the miscible process and driving flow of the carbon dioxide, water and oil multi-phase system in porous media are of great importance in the development of carbon dioxide enhanced oil recovery technology.In this project, the interphase mass transfer and driving flow process of the carbon dioxide / water / alkane three-phase system with chemical reaction are studied by means of microscale simulation, theoretical analysis and labotatory experiment.Molecular dynamics simulations of the miscible process and driving flow of the three-phase system will be carried out to analyze the influence of interphase mass transfer and chemical reaction on the driving flow. Interphase mass transfer model and modified non-Darcy effect model will be developed for numerical simulation of miscible flooding.The laboratory experiments of carbon dioxide / water / alkane three-phase flow in sand pack slim tube will be carried out. Numerical simulations with the experimental conditions will be peformed to verify the reliability of the developed models, which will serve the engineering application of carbon dioxide enhanced oil recovery technology..Investigating the complex miscible process and driving flow of carbon dioxide, water and oil in low permeability reservoirs are the interdisciplinary problem between engineering thermophysics and petroleum and natural gas exploitation. It involves nanoscale porous media, supercritical carbon dioxide, interphase mass transfer and chemical reactions between different fluids or between fluids and the core.The research in this project will help to understand the mechanism of multi-phase flow and interphase mass transfer in porous media under complex conditions, promote the development of engineering thermophysics.

研究多孔介质内二氧化碳、水、油多相体系复杂的混相及驱动流动规律对二氧化碳强化驱油技术的发展有重要意义。本项目拟采用微观模拟、理论分析、室内实验相结合的方法研究二氧化碳/水/烷烃三相体系带有化学反应的相间传质过程及驱动流动过程。从微观层面开展三相体系混相及驱动流动的分子动力学模拟，分析相间传质与化学反应对驱动流动的影响机理，建立可用于驱油数值模拟的相间传质模型及非达西效应修正模型。设计并进行填砂细管室内实验，针对实验工况开展数值模拟，验证模型的可靠性，为二氧化碳混相驱油的工程应用服务。.探究低渗透储层内二氧化碳、水、油复杂的混相及驱动流动规律是工程热物理与石油天然气开采学科间的交叉问题，涉及到纳米尺度的多孔介质孔隙、超临界态的二氧化碳、相间的传质、流体之间及流体与岩芯的化学反应。本项目拟开展的研究能够促进对复杂条件下多孔介质内多相流动与相间传质机理的认识，有助于工程热物理学科的发展。

本项目通过纳米孔膜直通道流动驱替实验与分子动力学及分子反应力场模拟相结合的方法，研究了二氧化碳及其化学反应产物对纳米孔多相渗流规律及相间传质规律的影响。实验方面设计并搭建了纳米孔通道流动驱替实验装置，测量了流体在不同孔径纳米通道内的流动规律及混相或非混相的驱替规律。模拟方面采用经典分子动力学方法研究了单相及多相渗流，揭示了壁面影响下流体粘弹性效应引起的非达西渗流行为，并建立了基于粘弹性性质的非达西渗流模型。模拟了纳米孔内的相间传质过程，揭示了壁面影响两相分子互扩散系数及流场分布，进而影响对流扩散过程的机理，并提出了修正的分散模型，能较好地描述纳米孔内对流扩散过程。通过分子反应力场方法研究了二氧化碳与水的化学反应对两相相间传质的影响规律，揭示了碳酸分子促进油水两相混相的微观机理。