东濮凹陷潜山成藏条件研究

Hydrocarbon accumulation condition of buried hills in Dongpu Depression

研究表明,东濮凹陷潜山主要有3种类型:侵蚀潜山、构造-侵蚀潜山和构造潜山,其分布主要受断裂控制。油气源为下第三系和上古生界地层。主要发育中生界、上古生界和下古生界3套储集层,储层物性以低孔、低渗为主,局部的缝洞发育提高了储集性能。水型和矿化度的变化反映出成藏条件的不同。地层水信息揭示出,该区潜山依据成油条件分为4个区:兰聊上升盘残丘区、兰聊下降盘北部地区、南部及东明集地区和混合水型区。各区成藏和保存条件不相同。东濮凹陷为断陷盆地,盆地内大大小小的断层众多,彼此互相切割,形成复杂的断裂系统,加上不整合面和侵蚀面一起构成立体式的疏导体系。潜山成因的不同类型,有着不同的供油方式。断层是控制成藏的重要因素。

Study shows that there are three main types of buried hills in Dongpu Depression,which are erosion buried hills,erosionstructure buried hills and structure buried hills.The distribution of buried hills are mainly controlled by the fracture.The Lower Tertiary source rocks and the Upper Paleozoic coal-bearing strata are the oil-gas source beds.The Mesozoic,Upper Palaeozoic and Lower Paleozoic reservoirs are developed,mainly with low porosity and low permeability.The localized development of fractures and holes improves reservoir performance.The changes of water types and salinity reflect the different reservoir forming conditions.The information on formation water indicates that there are four areas divided,which are the remaining-mound area of the upthrow side of Lanliao Fault,the northern area of downthrow side of Lanliao Fault,the south and Dongmingji Area and the mixed water type areas.The reservoir forming and the preservation conditions in the four areas are different.Dongpu Depression is a faulted basin and there are numerous,large or small faults that cut each other mutually,forming the complex fracturing system.In addition,the plane of unconformity and the erosion surface constitute the stereoscopic unblocking system together.The different genetic types have the different oil supply ways and faults are important factors in controlling the accumulation of buried hills.