三塘湖盆地石炭系成藏要素及有利勘探方向

石炭系地层在三塘湖盆地广泛发育，沉积了巨厚的海陆过渡相烃源岩，并建造了巨厚的火山岩系，形成了独立的含油气组合。岩相、岩性决定了火山岩储集层的先天条件，为后期风化淋滤奠定了基础；火山岩储集层经历了两期风化淋滤，形成了产状和产液能力均不同的两套储集层；鼻状构造背景形成油气运移的低势区，决定了油气运聚方向；后期构造裂缝的形成改善了储层渗流特性，决定着储层产液能力。在分析油藏主控因素的基础上，指出了三塘湖盆地北东向展布的鼻状构造带是火山岩风化壳油气藏有利的勘探领域，而淖毛湖、汉水泉乌通等勘探及认识程度较低的凹陷是下步风险勘探领域；南缘逆冲构造带是寻找孔隙一裂缝性油藏的有利勘探领域。对该区的石炭系油气勘探具有重要意义。

Key Factors of Carboniferous Hydrocarbon Accumulation and Favorable Prospecting Regions in Santanghu Basin

In Santanghu basin,Carboniferous stratum develops widely,and sea-to-terrene transitional facies hydrocarbon source rocks deposit bulkily,and ultra-thick lava builds enormously,and independent hydrocarbon-bearing compounding shapes.The lithofacies and lithology determine the formation connatural qualification,and establish the base to be airslaked and eluviated later.The lava formation undergoes two periods of airslaked and eluviated,and so two series formations,different in formation occurrence and producti...