Effected by nearly NS-trending tensile stress, Bozhong sag Paleogene mainly developed nearly EW-trending and NW-trending syndepositional fault in different levels,which control the structural form of sag and sub-sag respectively.According to the variety of bed thickness of Paleogene different stratum,syndepositional fault and uplift or long-term submarine uplift are taken as the boundary, Bozhong sag could be divided into four sub-sags, Dongbei sub-sag,Dongnan sub-sag,Xibei sub-sag and Xinan sub-sag.The degree of development and special con-figuration of tectonic steep slope zone,sedimental gentle slope zone and low uplift zone differ in different sub-sags. Combine with well-log and seismic data,sedimentary facies analysis indicate that steep slope zone which adjoin up-lift mainly develops short distance progradational fan delta,gentle slope zone mainly develops long distance progra-dational braided river delta and low uplift zone mainly develops shallow lacustrine deposit.Es3 and Ed3 are intense faulting periods and Es1 is brackish water period,which are main development periods of hydrocarbon source rocks in Bozhong sag.After recover geochemistry relevant parameter of hydrocarbon source rocks,apply PetrolMod to an-alog compute hydrocarbon generation quantity and hydrocarbon expulsion quantity of all sub -sags.The results show that Es3's quantity of resource is best, Ed3's and Es1-2's take second place on vertical profile.Dongbei sub-sag's quantity of resource is richest,followed by Xinan sub-sag,Dongnan sub-sag and Xibei sub-sag on the plane. Up to now,discovered oil deposit and oil gas almost derive from Es group.Fault is main migration pathway of hy-drocarbon migrating to shallow.Controlled by fault migration pathway system,main oil-gas exploration direction in different sub-sags is clearer.%渤中凹陷古近纪受近南北向拉张应力影响,形成了近EW向和NW向为主的不同级别同沉积断裂,分别控制了凹陷和洼陷的结构形态.依据古近系不同层段的地层厚度变化,以同沉积断裂、凸起或长期发育的水下隆起为边界,可将渤中凹陷划分为东北洼陷、东南洼陷、西北洼陷和西南洼陷共计4个洼陷,构造陡坡带、沉降缓坡带、低隆起带在不同洼陷发育的程度和空间配置各不相同.井震结合的沉积相分析表明,古近纪各洼陷的毗邻凸起的陡坡带多发育短距离进积的扇三角洲,缓坡带多发育较长距离进积的辫状河三角洲,低隆起带往往以滨浅湖沉积为主.沙三段、东三段强烈断馅期和沙一段半咸水期是渤中凹陷烃源岩的主要发育期.经恢复烃源岩地球化学相关参数后,利用PetrolMod软件,模拟计算各洼陷的生烃量和排烃量,结果显示:垂向上沙三段形成的资源量最大、其次为东三段和沙一二段;平面上东北洼陷资源量最为丰富,随后是西南洼陷、东南洼陷、西北洼陷.目前发现的油藏油气几乎均源于沙河街组,断层是油气运移到浅层的主要运移通道.在断层输导体系控制下,明确了不同洼陷的主要油气勘探方向.
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