| “Make use of both domestic and foreign resources”is China’s energy strategy. Research shows that Triassic Basin of Algeria in Africa has rich remaining oil and gas and it is one of the most imporatant preferred regions that China is going to cooperate with in oil and gas exploration.Richness remaining oil and gas,lackness of Petroleum geology research,unclear rules of oil and gas accumulation and data fragmentation,previous researches about Triassic Basin is limited to some basic geological problems rather than petroleum geology and petroleum system.Domestic research on this area is especially weak.All of these factors have affected the overall understanding of oil and gas potential in Triassic Basin and had a negative impact on China’s oil companies in choosing favorable exploration blocks.The petroleum geology data about Triassic Basin was summed up and studied by using the theory of petroleum accumulation dynamics.It include:the characteristics and evolvement of structure,the distribution of strata,the history of deposit and the characteristics of the Palaeozoic strata.Base on these,and according to the structure-sediment cycle and the development position of the maximum flooding surface,the accumulation dynamic system of the Triassic Basin was identified and classified.It was divided into 6 subsystems from bottom to top,among whichⅠthe bottom Cambrian allogenic-mixed accumulation dynamic subsystem,Ⅱlower Ordovician autogenous-allogenic accumulation dynamic subsystem,Ⅲmiddle Silurian autogenous accumulation dynamic subsystem,Ⅳmiddle Devonian allogenic-autogenous accumulation dynamic subsystem,Ⅴupper Carboniferous-Triassic allogenic- mixed accumulation dynamic subsystem andⅥtop Jurassic-Cretaceous allogenic- mixed accumulation dynamic subsystem.The unconformable surfaces and the crossing faults compose the connecting system.The accumulation dynamic system and the connecting system compose the 3D interspace web system. This thesis analyzed the conditions and actions of dynamic subsystems for hydrocarbon accumulation by the numbers.Models for hydrocarbon accumulation were constructed by traps of different styles that oil and gas had migrated from source rocks to traps.That is to say,main models for hydrocarbon accumulation were Named by three major elements of hydrocarbon accumulations(source,migration manner,the place for Oil and gas accumulation).The typical oil and gas fields were dissected.By the study about conditions and actions of dynamic subsystems for hydrocarbon accumulation in Triassic Basin,This thesis summarized the hydrocarbon accumulation,compared the exploration potential of every hydrocarbon accumulation dynamic subsystem,pointed out the favorable exploration aspect,and finally evaluated CNPC’s 438b and 350 blocks. |
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