华北盆地埋藏地貌面与油气藏

华北盆地白垩纪以来的地层中蕴藏着8个不同尺度的地文期。每个地文期都由初期的侵蚀面—河床滞留物质、早期的粗粒物质、中—晚期的细粒物质和末期的风化壳组成。华北盆地有2个埋藏地貌面——准平原和风化壳,分别位于基底拗陷区和基底隆起区的基岩面上。溶洞、孔洞、孔隙、裂隙十分发育的地貌面与地文期初期的侵蚀面、早期的粗粒物质堆积相互重叠的地区,为石油、天然气的储集提供了理想的场地。

Discussion on Correlation of Embedding Geomorphic Surface and Petroleum and Natural Gas Reservior in North China Basin

The stratum of North China Basin since Cretaceous contain 8 physiographic periods of different scale.Each of them is made up of detained corrosive surface-riverbed substance in early days and thick-granule substance in early stage and thin-granule substance in middle-later stage and weathering crust in last stage.There are two embedding geomorphic surfaces in North China Basin,namely,peneplain and weathering crust,which located on bedrock surfaces of floor downwarping region and floor upwelling region respectively.The geomorphic surfaces which develop solution holes and cavern and pore space and fissure very much as well as corrosive surfaces in early stage of physiographic period and regions of overlapped thick-granule substance cumulation provided perfect fields for concentration and storage of petroleum and natural gas.It embodies in five aspects as follows:1) The granule in Cretaceous,Paleogene and the upper half of Neogene established the basis for formation of petroleum and natural gas;2) The coarse material in Cretaceous geomorphic surface and the lower half of Paleogene provided perfect fields for new-production and ancient-deposition of petroleum and natural gas;3) The fluvial sand body in the lower half of the hypo-physiographic period of Paleogene provided perfect fields for self-production and self-deposition of Paleogene oil layer;4) The coarse material in Paleogene geomorphic surface and the lower half of Neogene physiographic period provided perfect fields for bottom-production and top-deposition of petroleum and natural gas;5) The coarse material in the lower half of Neogene physiographic period provided perfect fields for bottom-production and top-deposition of pyrolytic gas and for self-production and self-deposition of biogas.