【作者】 李君文；

【导师】 陈洪德；

【作者基本信息】 成都理工大学 ， 沉积学， 2007， 博士

【摘要】 环渤海湾地区下古生界以一套相对稳定的海相碳酸盐岩沉积为特征，多年来众多学者对其从各个方面进行了深入研究，但是在油气勘探方面尚未获得重大的突破。论文以沉积学、层序地层学理论等为指导，以层序演化—沉积演化—成盆演化为主线，以野外主干剖面、区域地层资料、钻井岩芯及测井资料综合分析为基础，对环渤海湾地区下古生界进行了层序地层划分和对比，建立了该区下古生界层序地层格架。通过点面结合，编制了层序岩相古地理图，揭示了不同时期层序岩相古地理的演化和分布规律，以期为油气勘探提供参考。主要成果和认识有：(1)运用现代地层学多重地层划分对比的原理，对研究区下古生界进行了较为系统、全面的清理和对比。(2)在大量野外剖面详细观测和钻井岩芯描述的基础上，识别出了层序底界面的物质表现形式有8种类型，层序界面可归结为4种成因类型：造山侵蚀层序不整合界面、隆升侵蚀层序不整合界面、海侵上超层序不整合界面、陆上暴露层序不整合界面。(3)下古生界寒武纪划分为13个三级层序和2个超层序(二级)，奥陶纪划分为11个三级层序和2今超层序。详细分析了层序地层单元的基本特征、叠置关系及空间分布规律，建立了研究区下古生界的等时层序地层格架。(4)从海平面变化、沉积物供应、构造沉降和气候等各个方面讨论了层序发育的主要控制因素，揭示了海平面变化对层序发育和沉积体系域分布的主要控制作用。(5)以超层序体系域为单元，编制了研究区下古生界超层序岩相古地理图9张，揭示了不同体系域期的层序岩相古地理特征及其演化；针对下古生界重点层位，以三级层序为编图单元，编制了7张层序岩相古地理图。所编制的层序岩相古地理图具有等时性、成因连续性和实用性等特点。(6)通过对超层序地层格架中的烃源岩、储集层和盖层的分布规律、组合特征分析认为：无论是生烃潜力还是储层品质，奥陶系普遍优于寒武系。(7)通过对奥陶系碳酸盐岩潜山油气藏的地质特征分析，探讨了后期构造运动对奥陶系储层的改造作用。更多还原

【Abstract】 The lower Paleozoic is a set of relatively stable marine carbonate rocks deposition around Bohai Gulf area. For many years many researchers have studied the area from each aspect in detail, but not yet obtains the significant breakthrough in the oil gas exploration. This thesis according to the theory of sedimentology and sequence stratigraphy and so on, taking the sequence evolution, deposition evolution and basin evolution as the master line. On the basis of the field section, the region stratum material, the generalized analysis of drill-core and log information, then dividing and contrasting the sequence stratigraphy of the lower Paleozoic around Bohai Gulf area, then establishing sequence stratigraphic framework. With the combination of point and face, working out sequence lithofacies palaeogeography map and studying sequence palaeogeographic evolution and distribution of various periods in order to provide reference to oil-gas exploration. The main achievement and the understanding are generalized as follows:(1)Using the modem stratigraphy multiple stratum division and contrast principle to systematically and comprehensively clean up and contrast the lower Paleozoic in study area.(2)Basing on the massive field sections observation and the drill-core description in detailed, eight types sequence bottom boundary were identified, the sequence surface can be summed up four genetic types which are the orogenic erosional sequence unconformity, the uplift erosional sequence unconformity, the transgressive onlap sequence unconformity and the exposed sequence unconformity.(3)The lower Paleozoic Cambrian can be partitioned into 13 third-order sequences and 2 supersequences(the second-order), and the Ordovician can be partitioned into 11 third-order sequences and 2 supersequences. The basic characteristic of sequence stratigraphy unit, thestacking relations and the spatial distribution rule have been analysised detailedly and then established isochronal sequence stratigraphy framework of the lower paleozoic in the study area.(4)According to the sea-level change, the deposit supply, the tectonic subsidence, the climate and so on, the main controlling factors of sequence development is discussed in this thesis, then revealed the primary control function of the sea-level change to the sequence development and the depositional system tract distribution.(5)Nine supersequence lithofacies palaeogeography maps in the study area lower Paleozoic have been compiled on condition of supersequence system tract used as drawing unit, it reveals the characteristic and evolution of lithofacies palaeogeography of different system tract period; In view of the key formation of lower paleozoic, seven lithofacies palaeogeography maps have been compiled on condition of third-order sequence used as drawing unit, all of these palaeogeography maps have characteristic of isochronism, success of the sedimentation process and practicality.(6)Through analysis to the distributed rule and the combination characteristic of hydrocarbon source rock, the reservoir and the cap rock in the supersequence stratigraphic framework, it is believe that the fresh hydrocarbon-generation potential and the reservoir quality of Ordovician are better than that of Cambrian in the study area.(7)In the light of analysis the geologic characteristic of Ordovician carbonate rocks buried hill hydrocarbon reservoir, the transformation function of the later period tectonic movement to the Ordovician system reservoir is discussed.更多还原