【作者】 付彦辉；

【导师】 吴时国；

【作者基本信息】 中国石油大学 ， 矿产普查与勘探， 2009， 硕士

【摘要】 深水水道沉积体系是被动大陆边缘常见的一种深水沉积过程。作为陆源碎屑沉积物向海底搬运的主要方式,在深海沉积中占有重要的作用。同时,深水水道沉积体系是深水油气的主要储层,是深水油气勘探的重要目标。本文以琼东南盆地南部陆坡中新世以来的深水水道沉积体系为研究靶区,根据地震地层学、层序地层学和石油地质学等理论,以地震资料为基础,结合邻区测井资料,识别出研究区域深水水道沉积体系,进一步分析中新世以来多期深水水道、朵叶体和席状砂沉积特征及其分布。研究区内深水水道沉积体系具有复杂的发育形态、分布特征。这些深水水道沉积体系主要受控于南海北部陆缘海平面的变化和陆坡演化特征。深水水道沉积体系对应于南海的大规模海退,其中主要有21Ma、16.5Ma、l5.5Ma、12.5Ma、10.5Ma、8.2Ma、5.5Ma七个低水位时期。同时,陆坡演化也对深水水道体系有着重要的影响,把陆坡演化下的深水水道沉积体系分为两个时期。第一个时期为早中新世,此时研究区域的陆架-陆坡-海盆格局尚未形成,发育有陆坡充填型沉积体系。第二个时期为中中新世以后,该时期大量陆源碎屑沉积物的充填使陆坡盆地基本被填平,现代意义的陆架-陆坡-海盆的地形格局已经形成。在海平面大幅度下降期间,大量沉积物越过陆坡注入海盆;在海平面下降幅度相对较小时期,沉积物主要在陆架相邻的陆坡位置堆积。通过对研究区域烃源岩条件、圈闭条件和运聚条件分析,认为该区深水水道沉积体系的砂体可以构成良好的岩性圈闭和地层构造复合圈闭,具有良好的油气远景。更多还原

【Abstract】 Deep-water channel systems(DCSs) is one kind of the deep water sedimentation of the passive continental margin. it is the main conduits to transport terrigenous clastic sediments into deep sea.it takes an important position in the deep sea sediments. and at the same time DCSs is the major reservoirs for the deep water exploration.Based on the theories such as seismic stratigraphy, sequence stratigraphy, petroleum geology, et,al. multiple stages DCSs since Miocene have been discerned in the southern slope of Qiongdongnan basin.by using seismic data and log parameter nearby. The sedimentary characteristic and distribution of deep-water channels, lobes and sheet sands in the DCSs have been indentified and analysed in the study area.The DCSs has comflex geomorphology and distribution which were controlled by the sea level fluctuations and the slope evolution. The development of DCSs are corresponds to relate sea level change and slope evolution in the northern South China Sea margin, The scale of sea level fluctuations occur in Miocene and Pliocene(21Ma、16.5Ma、l5.5Ma、12.5Ma、10.5Ma、8.2Ma、5.5Ma). and the slope evolution is also an important effect of the DCSs.In the early Miocene,there are no complete shelf-slope-basin system. The deep channel system settled in the slope basin.Since the middle Miocene, the shelf-slope-basin system was well developed.The clastic sediments were transported into basin floor via the filled slope basin.With drop of the large scale of the sea level,DCSs sediments deposit mainly in the basin floor.on the other hand,with drop of small fluctuation of sea level,the DCSs deposits in the slope basin.Through analyse of the hydrocarbon source rocks,the trap condition,and the migration path and accumulation condition in the study area.Miocene DCSs sand bodies are well loghological trap and the strata-structure combination trap,and has the good hydracarbon prospect.更多还原