山东济阳坳陷二氧化碳气成藏模式分析

山东济阳坳陷CO2气藏类型众多,成藏模式存在多样性。根据CO2气藏组分含量和同位素的分析结果,发现济阳坳陷CO2气藏以幔源成因为主,岩浆气源体是最重要的CO2气源体,火山岩体、火山通道和岩浆气源体附近的断裂对CO2气的运移成藏起关键作用。通过卸压条件下CO2的运移、CO2在断裂(裂缝)中的运移、CO2在孔隙—裂缝双重介质中的运移、CO2在砂质沉积物中的运移等一系列实验模拟,研究岩浆释出CO2气的运移成藏过程。结合已知气藏的运移成藏地质过程,建立济阳坳陷CO2气藏的3种地质模式,即侵入体—断裂—储集层转折成藏模式、侵入体—储集层直接成藏模式和埋藏火山通道—储集层直接成藏模式,为济阳坳陷CO2气成藏研究及其综合勘探奠定基础。

Analysis on CO2 Reservoir-Forming Patterns in Jiyang Depression,Shandong

There are many types of CO_(2) reservoirs,and the diversities of reservoir forming are identified in(Jiyang) depression,Shandong.The genesis of CO_(2) reservoirs was analyzed by component content and isotope(analysis) of CO_(2) reservoirs.The result shows that mantle-resource gas is the key genesis,and the magma gas source body is the most important source of the CO_(2).The volcanic body,volcanic conduit and the breaking near the magma gas source body played an important role in CO_(2) migration and reservoir forming.The processing of CO_(2) migration and reservoir forming were analyzed by a set of modeling experiments,such as CO_(2) migration(under) pressure release,in fissure,in porosity-fissure and in sand deposits,and combined with the given migration and forming processing to construct three reservoir-forming modes,which are intrusion-breaking-reservoir dogleg,direct intrusion-reservoir forming and direct buried volcanic conduit-reservoir forming.It lays a foundation for researching the CO_(2) reservoir-forming and integrated exploration in Jiyang depression.