渤中凹陷古近纪的洼陷分布、充填特征与勘探方向

发布时间：2019-01-20 10:16

【摘要】：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Petrol Mod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。
[Abstract]:The Paleogene of Bozhong sag was affected by the tensile stress of the near north and south direction, forming different synsedimentary faults in the near EW direction and NW direction, which controlled the structural morphology of the depression and the depression respectively. According to the variation of formation thickness in different strata of Paleogene, taking synsedimentary fault, uplift or long-developed underwater uplift as the boundary, the Bozhong depression can be divided into four sag: northeast sag, southeast sag, northwest sag and southwest sag. The degree and spatial distribution of structural steep slope zone, subsidence gentle slope zone and low uplift zone are different in different sag. The analysis of sedimentary facies combined with well and earthquake shows that fan delta with short distance precession is developed in steep slope zone adjacent to uplift of Paleogene depression, braided river delta with long distance precession is developed in gentle slope zone, and shoreline shallow lake deposit is dominant in low uplift zone. The main developing periods of source rocks in Bozhong sag are the strong filling stage of the third member of Shahejie formation and the brackish water period of the first member of Shayi formation. After recovering the geochemical parameters of source rocks, the hydrocarbon generation and hydrocarbon expulsion of each sag are simulated and calculated by using Petrol Mod software. The results show that the formation of resources in the third member of vertical upward sand is the largest, followed by the third member of the east and the second member of the first and second member of Shahejie formation. The northeast sag is rich in resources, followed by southwest sag, southeast sag and northwest sag. At present, almost all of the oil and gas are discovered from Shahejie formation, and fault is the main migration channel for oil and gas migration to shallow layer. Under the control of fault migration system, the main oil and gas exploration directions of different sag are determined.
【作者单位】：中国石油大学(华东)地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;大庆油田采油八厂;
【基金】：国家科技重大专项(2008ZX05023-001-004-002,2011ZX05023-001-013)资助
【分类号】：P618.13

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