The dry wells in northern sub-sag belt of the Zhu-1 Depression,indicates that the "source" and "migration"account for a large proportion of well failure and are the two key controlling factors of hydrocarbon accumulation.For the source presence,based on seismic facies and geochemical analysis,five of the eight subsags,developing deep or semideep lacustrine source rocks,are identified to be favorable for hydrocarbon generation.For the migration,according to structural belt analysis on the plane view,five subsags in northern subsag belt feature gentle slope belt favorable for hydrocarbon enrichment.In vertical perspective,according to analysis of faults and Enping Formation mudstone sealing conditions of the five subsags,three of them belong to the shallow strata sealing type and the other two belong to the deep strata sealing type,favorable for shallow and deep accumulations respectively.%珠—坳陷北部洼陷带已钻井失利原因分析表明,因“烃源”和“运移”问题而失利的井所占比例最大,这两个关键因素即为该区的油气成藏主控因素.从烃源条件来看,根据地震相和地球化学分析,北部洼陷带的8个洼陷中,有5个洼陷发育文昌组半深湖-深湖相优质烃源岩,是今后进行油气勘探较为有利的富生烃洼陷.从运移条件来看,平面上根据油气富集构造带类型分析,北部洼陷带内的5个富生烃洼陷均属于“缓坡富集型”,各洼陷的缓坡带是有利勘探区带;而纵向上根据通源断裂及恩平组泥岩封盖条件分析,北部洼陷带内的5个富生烃洼陷中,有3个属于“浅层富集型”,有2个属于“深层富集型”,其有利勘探层系应分别在浅层和深层.
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