一种用于确定饱和低渗透砂岩岩心中超临界CO_(2)突破压力的数值方法  

A Numerical Method for Determining Supercritical CO_(2)Breakthrough Pressure in Saturated Low-permeability Sandstone core

作　　者：赵世宇 李铱 索瑞厅 于青春[3] ZHAO Shiyu;LI Yi;SUO Ruiting;YU Qingchun(School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,Inner Mongolia Autonomous Region,China;School of Civil Engineering,Tianjin University,Jinnan District,Tianjin 300350,China;School of Water Resources and Environment,China University of Geosciences(Beijing),Haidian District,Beijing 100083,China)

机构地区：[1]内蒙古大学生态与环境学院,内蒙古自治区呼和浩特市010021 [2]天津大学建筑工程学院,天津市津南区300350 [3]中国地质大学(北京)水资源与环境学院,北京市海淀区100083

出　　处：《中国电机工程学报》2021年第4期1250-1257,共8页Proceedings of the CSEE

基　　金：国家自然科学基金(41702251);内蒙古自然科学基金(2019MS04018);江苏省煤基温室气体减排与资源化利用重点实验室创新项目(2019B005)。

摘　　要：CO_(2)突破压力在CO_(2)地质储存能力、场地选择和盖层安全性评价中起着重要作用。为探究可用于预测CO_(2)突破压力的数值模拟方法,研究通过使用COMSOL Multiphysics数值软件,提出了一种基于逐步法的数值方法,并对饱和低渗透岩心进行了CO_(2)突破压力的数值模拟。结果表明:当岩心完全饱水时,CO_(2)突破压力和突破时间分别5.4 MPa和70 h,通过与已有实验数据对比,证明了此模拟方法是合理的。同时,对CO_(2)-H_(2)O系统中的界面张力和VG模型中m/l值进行了敏感性分析,结果表明:在相同的界面张力条件下,m/l参数越大,CO_(2)突破压力和突破时间越大。另外,随着CO_(2)-H_(2)O系统中界面张力的增大,突破压力和突破时间均呈减小趋势。研究可为深入研究岩心尺度上的CO_(2)突破行为和盖层评价等提供数值信息。CO_(2)breakthrough pressure plays an important role in CO_(2)geological storage capacity,selecting target storage sites and assessing the safety of caprock.In order to explore the numerical simulation method that can be used to predict the CO_(2)breakthrough pressure,a numerical method based on step-by-step method was proposed by using the numerical software of COMSOL Multiphysics,and the numerical simulation of CO_(2)breakthrough pressure in a saturated low-permeability rock core were carried out.The results show that when the rock core is completely saturated with water,the breakthrough pressure and breakthrough time of CO_(2)were 5.4 MPa and 70 h,respectively.Compared with the experimental results,it is proved that the numerical simulation is reasonable.Meanwhile,sensitivity studies on the interfacial tension in CO_(2)-H_(2)O systems and the key parameters of m/l values in van Genuchten(VG)model are carried out.The results show that,under the same interfacial tension,the greater the m/l parameters,the greater the CO_(2)breakthrough pressure and time.In addition,with the increase of interfacial tension in CO_(2)-H_(2)O systems,the breakthrough pressure and time both tend to decrease.This study provides numerical information for further studies on CO_(2)breakthrough in rock core and the evaluation of caprock.

关 键 词：CO_(2)地质储存 CO_(2)突破压力 数值模拟 逐步法 敏感性分析 

分 类 号：P641[天文地球—地质矿产勘探] P66[天文地球—地质学]