黄骅坳陷王官屯构造带白垩系火山岩油气成藏特征

黄骅坳陷王官屯构造带白垩系火山岩发现了多口高产井，油气较为富集。为了探讨该油气成藏的主控因素，分析王官屯构造带火山岩油气地质特征，结合包裹体及埋藏史，明确了油气成藏的期次和成藏模式。结果表明：王官屯构造带油气来源于孔店组孔二段暗色泥岩和页岩；火山岩储层岩性为熔岩、火山碎屑岩和火山碎屑沉积岩，可划分为4类岩相、7种亚相；原生储集空间主要包括气孔、晶间孔、粒间孔及收缩缝，次生储集空间主要为高孔构造裂缝及溶蚀孔隙，发育两大类有利储层；火山岩具有2套储盖组合，即地垒构造圈闭及断鼻构造圈闭；油气充注期开始于晚渐新世，持续至今，为典型的“新生古储”侧向供烃油气成藏模式。该区油气成藏主控因素为：供烃窗口控制源岩侧向供烃，构造缝与溶蚀作用改善储集性能，构造样式及演化控制油气保存与聚集。

Hydrocarbon accumulation characteristics of Cretaceous volcanic rocks in Wangguantun tectonic zone,Huanghua Depression

Many high-yield wells have been found in Cretaceous volcanic rocks in Wangguantun tectonic zone, and oil and gas are enriched. In order to explore the main controlling factors of hydrocarbon accumulation,combined with inclusions and burial history,the petroleum geologic characteristics of Cretaceous volcanic rocks were analyzed,and hydrocarbon accumulation stages and model were defined. The results show that the Cretaceous oil and gas in Wangguantun tectonic zone originated from dark mudstone and shale of the second member of Kongdian Formation. The volcanic reservoir was dominated by lava,pyroclastic rocks and pyroclastic sedimentary rocks. The lithofacies can be divided into four lithofacies and seven subfacies. Primary reservoir space mainly included pore,intercrystal pore,intergranular pore and shrinkage fracture,and secondary reservoir space mainly consists of high-porosity structural fracture and dissolution pore. There are two sets of reservoir-cap assemblages in the Cretaceous volcanic rocks,which have two types of traps:horst structure trap and fault nose structure trap. Its hydrocarbon filling period began in the Late Oligocene and lasted till now. It was a typical lateral hydrocarbon supply and accumulation model of Cenozoic-Mesozoic reservoir. The main controlling factors of hydrocarbon accumulation are that:hydrocarbon supply window controls lateral hydrocarbon supply of source rocks;structural fracture and dissolution improve reservoir performance;structural style and evolution control hydrocarbon preservation and accumulation.