松辽盆地伏龙泉断陷沙河子组层序地层与沉积体系研究

发布时间：2018-06-17 19:30

本文选题：伏龙泉断陷 + 沙河子组　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：伏龙泉断陷位于松辽盆地南部,处于东南隆起区与中央凹陷的交界带上。自白垩纪以来经历了多个构造演化阶段,白垩纪早期为箕状断陷盆地,由南向北分别发育顾家店次凹、伏南次凹和伏北次凹。本文以层序地层学、构造地质学、沉积学等为指导,结合岩芯、测井、地震以及测试分析等资料,对伏龙泉断陷沙河子组的层序地层特征和沉积体系特征进行综合研究,建立层序地层格架,明确沉积相类型以及沉积体系展布特征,进而进行有利油气勘探区带的预测。根据岩芯、录井、测井以及三维地震等资料,识别层序界面,将伏龙泉断陷沙河子组划分为3个三级层序SQ1、SQ2和SQ3,每个旋回进一步划分为低位体系域、湖侵体系域和高位体系域。由于受到幕式构造运动的影响,每个沉积层序的发育特征存在着差异,沉降中心有规律的迁移。沙河子沉积早期,为初始裂陷期,沉降中心在南部,顾家店次凹和伏北次凹沉积地层厚度较大于伏北次凹;沙河子中晚期,为快速裂陷期,沉降中心逐渐迁移到北部,三个次凹沉积厚度大致相等。伏龙泉断陷东部由南向北的3条边界断层分别控制了顾家店次凹、伏南次凹和伏北次凹的形成。重矿物、砂岩百分含量、古地貌以及各种地震属性等资料表明,研究区主要发育来自北西和南西向两大物源体系。通过分析岩芯相、测井相和地震相等识别标志,研究区沙河子组主要发育扇三角洲、近岸水下扇和湖泊等3种沉积相。研究区沙河子组扇三角洲可识别出扇三角洲平原、扇三角洲前缘两种亚相以及辫状河道、河道间、水下分流河道、水下分流间湾四种沉积微相。其中,扇三角洲前缘分布范围较广,是本区沉积的主体。扇三角洲前缘的水下分流河道和水下分流间湾为常见的微相类型。此外,在伏南次凹东部陡坡带发育近岸水下扇-湖泊沉积体系。研究区沙河子组的圈闭类型主要有下切谷充填圈闭、砂岩上倾尖灭圈闭、砂岩透镜体圈闭以及构造-岩性复合圈闭。综合烃源岩质量与分布、储集体特征、圈闭类型等成藏条件分析,认为伏北次凹西北缓坡带、伏北次凹东部陡坡带、伏南次凹南部背斜带以及顾家店次凹西北缓坡带为伏龙泉断陷沙河子组的有利油气勘探区带。
[Abstract]:The Fulongquan fault depression is located in the south of Songliao Basin and the junction zone between the southeast uplift area and the central sag. Since the Cretaceous period, there have been several tectonic evolution stages. In the early Cretaceous period, there were grabenlike faulted basins, and Gujiadian subconcave, Funan subdepression and Fubei subdepression were developed from south to north, respectively. Under the guidance of sequence stratigraphy, structural geology and sedimentology, combined with the data of core, logging, seismology and test analysis, the characteristics of sequence stratigraphy and sedimentary system of Shahezi formation in Fulongquan fault depression are comprehensively studied in this paper. The sequence stratigraphic framework is established, the sedimentary facies type and the distribution characteristics of sedimentary system are defined, and the favorable oil and gas exploration zones are predicted. Based on the core, logging, logging and 3D seismic data, the Shahezi formation in the Fulong Quan fault depression is divided into three third-order sequences SQ1, SQ2 and SQ3. Each cycle is further divided into low system tracts, lacustrine transgressive system tracts and high level system tracts. Due to the influence of the curtain tectonic movement, there are differences in the developmental characteristics of each sedimentary sequence, and the subsidence centers migrate regularly. In the early stage of Shahezi sedimentation, the subsidence center was in the south, the thickness of the sedimentary strata in Gujiadian subdepression and Fubei subdepression was larger than that in Fubei subdepression, and in the middle and late stage of Shahezi, the subsidence center gradually migrated to the north. The thickness of the three subconcave deposits is about the same. Three boundary faults from south to north in the east of Fulongquan fault depression controlled the formation of Gujiadian subconcave, Volonan subconcave and Fubei subconcave, respectively. The data of heavy minerals, sandstone percentage, paleogeomorphology and various seismic attributes indicate that the study area is mainly developed from NW and SW source systems. Based on the analysis of core facies, logging facies and seismic identification marks, three sedimentary facies, namely fan delta, nearshore underwater fan and lake, are mainly developed in Shahezi formation in the study area. The fan delta of Shahezi formation in the study area can identify four sedimentary microfacies: fan delta plain, fan delta front two subfacies, braided channel, interchannel, underwater distributary channel and underwater distributary bay. Among them, fan delta front distributes in a wide range and is the main body of sedimentation in this area. The subaqueous distributary channel and the interdistributary bay in the front of fan delta are common microfacies types. In addition, the near-shore fan-lake sedimentary system is developed in the steep slope zone in the eastern part of the subsag. The trap types of Shahezi formation in the study area are mainly lower cut valley filling trap, sandstone updip tip out trap, sandstone lens trap and tectonic-lithologic complex trap. Based on the analysis of source rock quality and distribution, reservoir characteristics, trap type and other reservoir forming conditions, it is considered that the northwestern gentle slope zone in Fubei subdepression and the steep slope zone in the east of Fubei subdepression. The southern anticline belt and the northwest gentle slope zone of Gujiadian subdepression are favorable oil and gas exploration zones of Shahezi formation in Fulongquan fault depression.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;P539.2

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