丽水凹陷是位于东海陆架盆地西南部的单断箕状凹陷。古近系地层是丽水凹陷内油气聚集的主要层位，具有较强的油气资源潜力。目前丽水凹陷仍处于勘探初期，不同学者对凹陷的基础认识尚不统一，这也成为制约丽水凹陷油气勘探的瓶颈问题。为解决这一问题，论文以层序地层学、地震地貌学及石油地质学理论为指导，综合应用地震、岩心、测录井，地球化学及古生物资料，建立层序格架和相对海平面变化曲线。结合岩心描述与典型地震相的识别和标定，在层序框架内开展沉积体系和砂体分布研究，明确所发育的沉积相类型。对重点的三维地震工区开展地震地貌学研究，建立沉积演化模式。最终根据区域成藏条件分析，确定油气分布的主控地质因素，利用盆地模拟方法结合地球化学分析，明确LS36-1油藏的成藏模式，指导今后的油气勘探工作。丽水凹陷古近系地层可划分出1个一级层序、3个二级层序和5个三级层序。在此基础上对每一个三级层序进行体系域划分，其中月桂峰组被划分为水进体系域（TST）和水退体系域（RST）；灵峰下段被划分为水退体系域（RST）和水进体系域（TST）；灵峰上段和明月峰下段被划分为下降体系域（FSST）、低位体系域（LST）、海侵体系域（TST）和高位体系域（HST）；明月峰上段被划分为水进体系域（TST）和水退体系域（RST）。在确定了丽水凹陷的层序划分方案后，通过对二维、三维地震资料、测井资料进行精细层位解释，最终建立了全区的层序地层格架。在此基础上，以Wheeler图为基础，综合古生物以及地球化学元素分析，建立了研究区古新世灵峰上段及明月峰下段的相对海平面变化曲线，该曲线形态与全球海平面曲线具有较好的对应关系。 通过对研究区65条二维骨架地震测线的精细解释，识别出研究区内存在前积、平行亚平行、楔状、河道充填4大类地震相，按照振幅、频率和连续性将其进一步划分为包括中强振幅-中低频-连续较连续反射相在内的9个地震相亚类，在此基础上编制了丽水凹陷的地震相平面图。此后利用岩心资料、钻井资料进行单井相分析，并对地震相进行标定，将地震相转换为沉积相图，在丽水凹陷内识别出三角洲、扇三角洲、斜坡群等多种沉积体系。通过精细三维地震地貌学研究，在明月峰下段及灵峰上段分别识别出了类陆架边缘三角洲及潮汐砂脊的沉积体系。明月峰下段的类陆架边缘三角洲沉积具有5个主要识别标志：a. 几何形态：坡折带之上发育沿走向分布的月牙状或长条状砂体。b.剖面特征：常常在坡折带之上形成大规模的超覆或进积砂体，陆架边缘砂体厚度甚至大于陆架中部和内陆架区域。c.陆架边缘向海一侧特征：破折带下常常具有浊流沉积，变形构造较为发育。d.陆架边缘向海一侧特征：陆棚边缘前段的坡折上常常具有冲刷痕迹或具有冲沟特征。e.陆架边缘向陆一侧特征：陆棚上接近陆架边缘的位置可能会出现河道下切的特征。灵峰上段的潮汐砂脊主要的两个主要特征：a. 岩心上可见典型的潮汐特征，包括压扁层理、双粘土层和对偶层。b. 几何形态： 沉积物平行分布并有显著的线性特征，这些定向的线性特征与古岸线垂直相交至斜交。烃源岩分析显示明月峰组主要发育以Ⅲ型干酪根为主的中等—较差烃源岩。灵峰组下段主要发育以Ⅱ型和Ⅲ型干酪根为主的中等—较差烃源岩。月桂峰组烃源岩发育以Ⅱ型与Ⅲ1型干酪根有机质为主的较好—好烃源岩。明月峰组及灵峰上段烃源岩在丽水凹陷大部分处于未成熟至低成熟演化阶段，灵峰下段和月桂峰组烃源岩均达到成熟－高成熟甚至过成熟演化阶段。坡折带及油源断裂是丽水凹陷岩性油藏的主控因素。丽水凹陷主要发育三种断裂坡折带和一种沉积坡折带，它们分别是：反向断阶型坡折带、同向断阶型坡折带、断坡型坡折带和陆棚边缘坡折带。发育有3种断裂疏导体系，分别是：正向断阶型疏导体系、反向断阶型疏导体系和边界断裂疏导体系。油源对比、流体包裹体分析和盆地模拟结果表明，LS36-1油藏凝析油气来源于月桂峰组及灵峰组烃源岩，共经历了两期充注。明月峰组沉积时期，灵峰组与月桂峰组产生的油气一起沿拉张形成的断裂系统运移至明月峰下段储层当中，形成早期的油藏。但此后地层遭受挤压抬升，对油藏起到破坏作用。在古新世末期至始新世初期，灵峰组烃源岩达到高成熟凝析油－湿气演化阶段，生成的凝析油气再次经断层运移至明月峰下段储层当中，形成LS36-1油气藏。

The NE-trending Lishui Sag in the East China Sea Shelf Basin (ECSSB), is a Cenozoic half-graben that evolved from a Mesozoic residual basement. Paleocene strata are currently the most productive of all chronostratigraphic units in the Lishui Sag. The exploration in the Lishui Sag is still in the early stage and it has failed to make remarkable progress in recent years due to the persistence of conflicting interpretation of sequence stratigraphy, sedimentary facies and hydrocarbon accumulation. Thus, a detailed petroleum geological analysis is required to guide future exploration and production efforts on the Lishui Sag. The researches of this article mainly focused on (1) establish the high frequency (fourth-order) sequence-stratigraphic framework and relative sea level curve of the Paleocene succession in the Lishui Sag using 3D seismic data, 2D seismic data, well logs, geochemistry, and paleontological data, (2) recognize the sedimentary facies in the Lishui Sag using 2D seismic facies analysis and depict the depositional systems distribution of the major target strata (Upper E1l and Lower E1m) using the 3D survey, and (3) investigate hydrocarbon charging history by employing an integrated approach involving source rocks evaluation, determination controlling factor of hydrocarbon accumulation, and hydrocarbon generation dynamic modeling. The ultimate intent is to provide explorers with additional tools and insight to aid in the development of the voluminous untapped Paleocene resources in the Lishui Sag.The Paleocene formation in the Lishui Sag was divided into one first order sequence, three second order sequence and five third order sequence. Two systems tracts, the transgressive and regressive systems tracts were recognized in the E1y, Lower E1l and Upper E1m strata. Four systems tracts, the falling stage, lowstand, transgressive and highstand systems tracts were recognized in the Upper E1l and Lower E1m strata. The stratigraphic framework was established in the Lishui Sag by using the 2D, 3D seismic survey and well log data. Bsed on the stratigraphic framework, the chronostratigraphic chart, geochemistry data and paleontological data were used to reconstruct the relative sea-level curve in the Lishui Sag. The result showed that the relative sea level curve had good correlation with the global sea level curve.Four types of seismic facies, including clinoform reflection, parallel-subparallel reflection, wedge shaped reflection and channel incision reflection had been recognized on the 2D seismic sections. They were subdivided into nine subcategories according to the amplitude, frequency and continuous. The seismic facies maps were converted to sedimentary facies maps based on the lithofacies analysis. Several depositional systems such as delta systems, fan delta systems and slop fan deposits had been recognized in the Lishui Sag. Based on the seismic geomorphology analysis, shelf edge delta and tidal sand ridges were imaged on the Lower E1m and Upper E1l strata respectively. The shelf edge delta deposits were recognized according to (1) The strike elongate sand bodies deposited on the shelf margin, (2) The large scale clinoforms that thickened towards the shelf edge, and thined gradually down onto the upper to middle slope, (3) soft-sediment deformation associated with sandy debris-flow deposits and high-density turbidites located on the shelf edge and slope, (4) The gullies and rills were believed to be initiated either as slide/slump scars or carved by sediment gravity flows on an oversteepened slope and (5) Channel-like erosional forms having fills observed at the top of prograding clinothem units were interpreted as shelf edge slide/slump scars. The tidal sand ridges were recognized according to (1) the striking linearity and parallel distribution of these deposits as observed on the seismic data and (2) the orientation of these elongated linear amplitude patterns orthogonal to oblique to the paleoshoreline.The E1m strata mainly distributed moderate - poor source rocks that contained type-III kerogen. The E1l strata mainly distributed moderate - poor source rocks that contained type II and III kerogen. The E1y strata mainly distributed good - moderate source rocks that contained type II and III kerogen. Source rocks in the E1m strata and Upper E1l strata had passed the hydrocarbon generate threshold or entered oil window stage, while had reached high to over mature stage in the Lower E1l strata and E1y strata. Slope break zones and drainage systems were the controlling factors of hydrocarbon accumulation. Four types of slope break zones developed in the Lishui Sag, including fault slope break belt, reverse fault slope break belt, fault break zone and shelf margin break zone. Three types of fault systems worked as drainage system in the Lishui Sag, including normal faults system, domino faults system, and listric faults system.Oil - source rock correlation, fluid inclusion analysis and basin modeling showed that the hydrocarbon in the LS36-1 reservoir mainly come from E1l and E1y source rock and the charge event of hydrocarbon took place between 51 and 23 Ma. During the E1m period, the oil and gas come from E1l and E1y source rocks were migrated to the E1m sandstones through fault systems, forming the LS36-1 reservoir at this stage. The tectonic uplift that happened at the end of Paleocene destroyed the formation of LS36-1 reservoir. At the initial stage of the Eocene, sediments subsided again and were buried deeper. The source rock in the E1l strata reached the high maturity stage and began to form condensate oil and wet gas. The oil and gas were migrated to the LS36-1 reservoir through the drainage system again, forming the secondary charge.