二氧化碳地质封存系统泄漏风险研究进展

Progress in Leakage Risk Study of CO_(2) Geosequestration System

CO_(2)地质封存技术是缓解温室效应的重要手段,而对于地质封存系统泄漏风险的评价是确保CO_(2)安全高效封存的前提。针对CO_(2)泄漏风险,系统论述了CO_(2)地质封存系统中井筒和盖层因素对CO_(2)泄漏风险的影响机理,包括固井质量、CO_(2)腐蚀及井筒组合体受交变应力损坏等,以及盖地比、盖层厚度、岩性等对盖层低速渗漏和高速泄漏的影响。最后,论述了基于上述影响因素综合作用下的井筒泄漏风险评价方法、盖层泄漏风险评价方法和CO_(2)封存系统泄漏风险综合评价方法,并指出了不同评价方法的优缺点。该研究可为CO_(2)地质封存工程中的选址、选层和泄漏风险评估提供理论支持。

CO_(2)geosequestration technology is an important method to mitigate the greenhouse effect,and the evaluation of leakage risk in geosequestration system is a prerequisite to ensure the safe and efficient sequestration of CO_(2).To address the risk of CO_(2)leakage,the influence of wellbore and caprock factors on the risk of CO_(2)leakage in CO_(2)geosequestration system was systematically discussed,including the quality of cementing,CO_(2)corrosion and damage to the wellbore assembly by alternating stress,as well as the influence of caprock-formation ratio,caprock thickness and lithology on low-speed seepage and high-speed leakage of caprock.Finally,the wellbore leakage risk evaluation method,the caprock leakage risk evaluation method and the CO_(2)sequestration system leakage risk evaluation method based on the combined action of the above influencing factors were discussed,and the advantages and disadvantages of different evaluation methods were pointed out.The study provides theoretical support for site selection,formation selection and leakage risk evaluation in CO_(2)geosequestration works.