摘要
碳封存是CO_(2)减排、缓解全球变暖等环境问题行之有效的方法。储层孔渗特性是决定CO_(2)封存效率的关键因素,其中,方解石型胶结酸蚀弱化是一种重要的影响机制,因而需要开展酸敏性弱胶结砂岩研究。开发酸敏性弱胶结人工砂岩制作方法,开展酸蚀过程酸敏性弱胶结砂岩变形分析,并探明酸蚀前后岩芯渗透率变化规律。首先,基于响应面法设计试验,研究不同脲酶活性、胶结液浓度、脱脂奶粉浓度对酸敏性弱胶结人工砂岩强度影响规律,建立考虑多因素的酸敏性弱胶结人工砂岩回归模型。其次,开展不同应力下酸敏性弱胶结人工砂岩酸蚀渗流试验,分析酸蚀过程岩芯变形规律:酸蚀过程中,岩芯体应变随酸蚀渗流量呈线性增长趋势,酸蚀渗流诱发的胶结弱化可使岩芯体缩应变超4%。最后,研究酸蚀前后岩芯渗透率变化:在高围压状态下,渗透率可降低70%。研究初步揭示了弱胶结砂岩酸蚀特性,对CO_(2)地质封存有一定的指导作用。
Carbon storage is an effective way to reduce CO_(2) emissions and mitigate environmental problems such as global warming.The porosity and permeability characteristics of storage reservoir are the key factors to determine the efficiency of CO_(2) storage,among which one important mechanism is the weakening of calcite cementation by acid erosion,and it is therefore necessary to carry out the researches on weakly cemented sandstone sensitive to acid.This study developed a prepare method of acid-sensitive weakly cemented artificial sandstone,conducted the deformation analysis of acid-sensitive weakly cemented sandstone during acid erosion process,and investigated the change laws of sandstone permeability before and after acid erosion.Firstly,based on the response surface experimental method,the effects of different urease activity,concentration of cementing fluid and concentration of skim milk powder on the strength of acid-sensitive weakly cemented artificial sandstone were studied,and a regression model considering multiple factors was established.Secondly,the acid erosion seepage tests of acid-sensitivity weakly cemented artificial sandstone under different stresses were carried out to analyse the deformation of sandstone during acid erosion:During acid erosion,the sandstone strain increases linearly with the acid flow,and the cementation weakening induced by acid erosion seepage can make the sandstone shrinkage strain exceed 4%.Finally,the change of sandstone permeability before and after acid erosion was studied:The permeability reduced by 70%under high confining pressure.The study reveals the acid erosion characteristics of weakly cemented sandstone,which has a certain guidance on CO_(2) geological storage project.
作者
杨昕
洪义
王立忠
国振
郑嘉男
颜梦秋
YANG Xin;HONG Yi;WANG Lizhong;GUO Zhen;ZHENG Jianan;YAN Mengqiu(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou,Zhejiang 310058,China;Hainan Institute of Zhejiang University,Sanya,Hainan 572025,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第6期1480-1491,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52122906)
国家自然科学基金重点项目(52238008,51939010)。
关键词
岩石力学
CO_(2)地质封存
酸敏性
弱胶结砂岩
响应面法
酸蚀渗流
rock mechanics
CO_(2)geological storage
acid sensitivity
weakly cemented sandstone
response surface method
acid erosion seepage
