含油、水多孔介质中CO2扩散传质过程研究

项目名称： 含油、水多孔介质中CO2扩散传质过程研究

项目编号： No.51206018

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 工程热物理与能源利用学科

项目作者： 赵越超

作者单位： 大连理工大学

项目金额： 25万元

中文摘要： 将CO2注入枯竭或低渗透油藏是实现提高采收率及解决温室气体地质埋存的有效方法，为了有效评价CO2驱油效率及地质埋存的安全性，必须对含油、水多孔介质中CO2扩散传质过程进行深入研究。本研究应用磁共振成像（MRI）技术对多孔介质孔隙度、渗透率、饱和度等参数实现可视化及量化分析，建立准确描述多孔介质孔隙结构的数字岩心模型；采用磁悬浮天平与MRI技术结合的双室压力衰减法对含油、水多孔介质中CO2扩散传质过程进行动态可视化检测，得到不同时刻、多孔介质中不同位置所赋存的流体的质子密度、纵向弛豫时间、横向弛豫时间及表观扩散系数分布图像，通过分析得到CO2溶解量与溶液密度、浓度、体积膨胀系数、弛豫时间、扩散系数的变化关系；对温度、压力、孔隙介质微观结构及流体物性等因素对CO2扩散过程的影响进行分析；在此基础上建立描述含油、水多孔介质中CO2扩散过程的物理与数学模型，从而揭示CO2扩散传质过程规律。

中文关键词： 二氧化碳；多孔介质；扩散系数；传质；磁共振成像

英文摘要： The method of injecting CO2 into depleted or low permeability reservoirs is an effective way for enhanced oil recovery and greenhouse gas geological storage. In order to effectively evaluate CO2 flooding efficiency and underground storage safety, it's necessary to study the process of CO2 diffusion and mass transfer in porous media saturated with oil and water. In this study, magnetic resonance imaging (MRI) is used to visualized and quantitative analyze the parameters in porous media, such as porosity, permeability and saturation. A digital core model is established which can accurately describe the pore structure of porous media. Then according to magnetic suspension balance and MRI technology, the dual-chamber pressure decay method is used to dynamically visualize the CO2 diffusion and mass transfer prosess in porous media saturated with oil and water, and obtain the fluid distribution images of proton density, longitudinal relaxation time, transverse relaxation time and apparent diffusion coefficient at different locations and time within the porous media. Through the analysis of experiment results, we obtain the relations of CO2 dissolved volume with the solution density, concentration, volume expansion coefficient, relaxation time and the diffusion coefficient. The impact factors of temperature, pressure,

英文关键词： CO2；porous media；diffusion coefficient；mass transfer；magnetic resonance imaging(MRI)