Analyzing On Conditions Of Oil And Gas Accumulation In The Southern-East Of North China Plate

In thought of the plate tectonics theory and staged mobilism, the basin evolution of the Southern-East of North China Plate(SENCP) is divided into 4 stages and 6 types by recovering denudation. After forming of metamorphic recrystallization of basement(Ar-Pt₁):1.the stage of "open"and "close" between the plates of North china and Yangtze(Z-D₂),including the stage of Craton-passive-continental margin(Z-O₂)and global uplift-(back-arc) basin(O₃-D₂);2. the stage of Craton ¨C(back-arc) foreland basin(D₃-T₁), including the stage of the foreland basin of flysch-deposition (O₃-D₂)and molasses-deposition(T₃-J₂);3.the action stage of the paleo-Pacific plates(J₃-K₂), including the stage of the intraorogenic bulk-subsidence and marginal detachment to basi(nJ₃-(K₁)¹),and uplift denudin(g(K₁)²-K₂);4. the action stage of the Pacific plate(E-Q), including the stage of rift-basin(E)and depression consumption(N-Q). By structure analyzing of seismic cross-section and regional structure maping,the structural style of ZhouKou is "the west-east direction being belt,the north-south direction dividing block",and exists three sorts of structure inversion :symmetrical inversion on one position,departural superimpositional inversion and fault-fold compound inversion.Its consist of two structural inversion zones in west-eastern direction:the northern zone is ShangQiu-XinZhen and the southern is LuYi-PingDinShan. The 200-400m coal measures starata of Permo-Carboniferous system is the essential composition of forming reservoir in the Southern-East of North China Plate by studying its hydrocarbon source rock.. The Middle-Upper Triassic and Middle-Lower Jurassic are local hydrocarbon source rocks of the north-western depressions, and the Lower Cretaceous is a local source rock of TanChuang depression in the middle area and HuangKou depression.in the north-eastern of SENCP. The Lower Tertiary is an important prospect strata of continental fault basin of Mesozoic-Cenozoic era that has more actual commercial. The Mesozoic-Cenozoic reservoirs are main target beds in SENCP?ˉs oil-gas exploration, and the intraformational sandstones of Permo-Carboniferous system benefit for gas-reservoirs of self-produce.The allite of Carboniferous bottom bed is a direct cap rock of reservoir that is the paleo-residue of Ordovician top bed.The mudstone of Permo-Carboniferous coal system and overlying Mesozoic-Cenozoic are important cap rocks of reservoirs of Paleozoic- Mesozoic. The anticlinal and semi-anticlinal traps are the first selected-targets of oil-gas exploration in SENCP. By method and principal of hydrocarbon system dividing,4 potential and inferred destructive systems are put out in SENCP?ˉs Paleozoic- Mesozoic, and they are classified to 8 potential and 5 inferred disruptive sub-systems. The hydrocarbon resources of Indo-Chinese and Yanshan and Himalayan cycle in Permo-Carboniferous system and Mesozoic of SENCP are counted by quantitative evaluation of "hydrocarbon regenerating" and multiple-generating and resource. Taking thought for most of hydrocarbon creating before Yanshan epoch are destroyed or bleeding, it is emphasized that hydrocarbon generating in Himalayan epoch contributed reservoirs.