老采空区CO_(2)封存井位部署方案数值模拟研究  

Numerical simulation of well location deployment scheme for CO_(2) sequestration in old goaf

作　　者：丁洋 汤远卓[1] 李树刚 赵泓超 朱冰[1] 张一正 张艳 DING Yang;TANG Yuanzhuo;LI Shugang;ZHAO Hongchao;ZHU Bing;ZHANG Yizheng;ZHANG Yan(College of Safey Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Key Laboratory of western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi’an University of Science and Technology,Xi’an 710054,China;Shaanxi Coal and Chemical Industry Group Co.,Ltd.,Xi’an 710100)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]西安科技大学西部矿井开采及灾害防治教育部重点实验室,陕西西安710054 [3]陕西煤业化工集团有限责任公司,陕西西安710100

出　　处：《煤炭科学技术》2024年第S2期131-141,共11页Coal Science and Technology

基　　金：国家自然科学基金面上资助项目(52374227);陕西省自然科学基础研究计划联合基金资助项目(2021JLM-26);陕西省自然科学基础研究计划面上资助项目(2024JC-YBMS-255)。

摘　　要：老采空区作为潜在的CO_(2)封存地质体,具有巨大的封存潜力。为明确不同井位部署方案下CO_(2)注入后在老采空区的分布特征及封存量,基于黄陵矿区试验煤矿的实际地质条件,在考虑老采空区内渗透率非均质性和煤岩吸附能力差异的基础上,运用COMSOL软件进行老采空区CO_(2)注入的数值模拟。研究表明:CO_(2)在老采空区的分布表现出越靠近底板、分布范围更广、浓度更高的趋势;当注入井井深达65m时,在老采空区上部低渗透区域的CO_(2)分布显著增加,而走向上分布范围显著减小,而且总封存量和游离态CO_(2)封存量分别达到最大值,分别为7.594×10^(6)kg和3.569×10^(6)kg;而注入井井深95 m时,吸附态CO_(2)封存量最大,总封存量中占比最高,分别为4.37×10^(6)kg和63.52%。增加监测井数量后,CO_(2)在老采空区走向上的分布范围显著扩大;此外,增加监测井数量并采用对称部署扩大了老采空区参与吸附封存的煤岩体范围,从而提高了CO_(2)在老采空区的封存量以及吸附态封存量的占比,该部署方式下CO_(2)封存量是单监测井部署的1.82倍以上,吸附态CO_(2)封存量占比从53.22%提高至72.693%以上。根据对分布特征和封存量的分析,得出了有利于提高老采空区CO_(2)封存量的纵向注入点位及监测井部署方式,可为CO_(2)在老采空区封存井位部署方案提供重要参考。As a potential CO_(2) storage geologic body,the old goaf has great storage potential.In order to clarify the distribution characteristics and storage capacity of CO_(2) injection in the old goaf under different monitoring well deployment schemes,based on the actual geological conditions of the experimental coal mine in Huangling Mining area,the numerical simulation of CO_(2) injection in the old goaf was carried out by using COMSOL software on the basis of considering the permeability heterogeneity and the differences in the adsorption capacity of coal and rock in the old goaf.The results show that the distribution of CO_(2) in the old goaf is closer to the floor,the distribution range is wider and the concentration is higher.When the depth of the injection well reaches 65m,the CO_(2) distribution in the low permeability area in the upper part of the old goaf increases significantly,while the trend distribution decreases significantly,and the total and free CO_(2) storage reach the maximum value,which are 7.594×10^(6) kg and 3.569×10^(6) kg,respectively.When the depth of injection well is 95 m,the storage of adsorbed CO_(2) is the largest,and the proportion of total storage is the highest,which are 4.37×10^(6) kg and 63.52%,respectively.With the increase of the number of monitoring Wells,the distribution range of CO_(2) in the strike of the old goaf is significantly expanded.In addition,by in creasing the number of monitoring Wells and adopting symmetrical deployment,the range of coal and rock mass in the old goaf participating in adsorption storage is expanded,thus increasing the proportion of CO_(2) sealed in the old goaf and adsorbed storage.Under this arrangement,the CO_(2) sealed stock is more than 1.82 times that of the single monitoring well.The proportion of CO_(2) storage in adsorbed state increased from 53.22% to 72.693%.Based on the analysis of the distribution characteristics and sealing stock,the longitudinal injection points and monitoring well deployment methods which are conducive to improving

关 键 词：老采空区封存 非均质性 COMSOL数值模拟 CO_(2)封存量 井位部署 

分 类 号：P618[天文地球—矿床学]