咸水层CO_(2)地质封存典型案例分析及对比

Analysis and comparison of typical cases of CO_(2) geological storage in saline aquifer

咸水层封存是CO_(2)地质封存方式中潜力最大的。目前全球比较成功的典型咸水层CO_(2)地质封存示范工程有挪威的Sleipner和Snøhvit、阿尔及利亚的In Salah、中国鄂尔多斯盆地神华,这些工程提供了长期CCS的经验,对于未来CO_(2)地质封存项目实施具有借鉴意义。从构造、储层、盖层等地质特征出发,结合各示范工程的注入方案和监测方案将各案例进行了剖析,提取了地质及工程参数,分析了各地质特征对CO_(2)地质封存的影响,明确了背斜、断块、裂缝等不同构造特征CO_(2)地质封存的可行性,对比了咸水层CO_(2)地质封存注入方案和监测方案。Sleipner CO_(2)地质封存项目成功的原因在于构造简单、面积大、储层物性好,盖层厚度大且稳定;Snøhvit发育的断层和In Salah的裂缝也验证了不同构造特征CO_(2)地质封存的可能性,CO_(2)羽流分布受地质特征的控制。咸水层CO_(2)地质封存注入井相对比较少,但是注入量比较大,多以水平井为主。高质量的监测数据可有效降低潜在泄漏风险,多种监测组合有助于CO_(2)长期安全地质封存。

The storage of saline aquifers has the greatest potential in the CO_(2) geological storage.At present,the successful demonstration projects of typical CO_(2) geological storage in the saline aquifer in the world include Sleipner and Snøhvit in Norway,In Salah in Algeria,and Shenhua in Ordos Basin,China.These projects provide long-term Carbon Capture and Storage(CCS)experience and are of reference significance for the implementation of future CO_(2) geological storage projects.Given the geological characteristics of the structure,reservoir,and caprock,this paper analyzed each case in combination with the injection and monitoring plans of each demonstration project and extracted geological and engineering parameters.Then,the influence of geological characteristics on CO_(2) geological storage was analyzed to clarify the feasibility of CO_(2) geological storage with structural features such as anticlines,fault blocks,and fractures.The injection and monitoring plans for CO_(2) geological storage in the saline aquifers were also compared.The following conclusions are drawn:①The success of the Sleipner CO_(2) geological storage project is attributed to the simple structure,large area,good physical properties of the reservoir as well as the large and stable caprock thickness.The faults developed in Snøhvit and fractures in In Salah also verify the possibility of CO_(2) geological storage with different structural characteristics,and the distribution of CO_(2) plume is controlled by geological characteristics.②There are relatively few injection wells for CO_(2) geological storage in saline aquifers,but the injection volume is relatively large,and horizontal wells dominate.③High-quality monitoring data can effectively reduce potential leakage risk,and a variety of monitoring combinations can contribute to the long-term safe CO_(2) geological storage.