【作者】 张晓杰；

【导师】 张立强；

【作者基本信息】 中国石油大学 ， 矿产普查与勘探， 2011， 硕士

【摘要】 本论文以东营凹陷北带中段古近系沙四上亚段为主要研究对象,利用地震、测井、录井、岩心以及分析化验等资料对本区目的层段进行层序地层和沉积相进行研究。综合地震、测井资料,在识别层序界面的基础上,将沙四上亚段自下而上依此划分为5个四级层序(SQ-1、SQ-2、SQ-3、SQ-4、SQ-5),每个层序以发育上升半旋回为特征。在此基础上,进行了地层的对比,建立了本区目的层段等时地层格架。根据相标志,结合单井相和剖面相划分,在研究区沙四上亚段识别出近岸水下扇、湖泊相和滑塌浊积扇等沉积相类型。通过岩性分布和地震反射特征的研究,结合沉积背景分析,认为本区共发育T174井区、T175井区、T75井区、T154井区四个北部物源区。利用砂岩百分比、地震相和地震属性相的平面分布,结合物源分析成果,综合分析了研究区各四级层序的沉积相展布。近岸水下扇在胜北断层上升盘广泛发育,规模大,并具有继承性发育的特点,滑塌浊积扇由近岸水下扇供源,主要发育在胜北断层下降盘,发育位置不固定,东西摆动、迁移频繁。在整个沙四上沉积期,由SQ-1到SQ-5,近岸水下扇逐渐向北部边缘迁移,浊积扇规模逐渐变小,形成明显的退积式沉积演化特征;各层序内部也具有退积式沉积特点,反映了湖盆间歇式扩张的沉积演化过程。扇体沉积主要受到了古沟道和断层的控制。在古沟道前方,扇体发育规模大,呈现沟扇对应的特点,且大沟对大扇、小沟对小扇;同时,胜北断层分隔了不同类型的的扇体,其上盘近岸水下扇广泛发育,下盘水深迅速增加,上盘上的不稳定沉积物沿陡的侵断层面向下搬运滑塌,形成滑塌浊积扇。更多还原

【Abstract】 The sequence stratigraphy and sedimentary facies of Upper Es4 of Paleogene in the middle section of north region of Dongying depreesion have been studied using seismic, well logging, mud logging, testing data and core information.Upper Es4 can be divided into five fourth-order sequences(SQ-1、SQ-2、SQ-3、SQ-4、SQ-5) according to the sequence boundaries recognized by methods of classic sequence stratigraphy using both well logging data and seismic data. Each sequence develops at the half cycle of increasing. On the basis of the fourth-order sequence framework, the short-term base-level cycles are subdivided and correlated by drilling, well logging and 3D seismic data. In the end , the isochronous stratigraphic framework is established.There are three types of sedimentary facies developed in the Upper Es4 including nearshore subaqueous fan, lacustrine facies and slump turbidite fan which are indicated by sedimentary facies marks of both petrology and geophysics as well as the analysis of single-well facies and cross-sectional facies.Four provenances lying in the north of the study area are analyzed by the characteristics of lithology distributions and seismic reflections under the sedimentary background which include well blocks of Tuo174 Tuo175, Tuo75 and Tuo154.The characteristics and distributions of sedimentary facies of upper Es4 are summarized in light of the horizontal distributions of sand-ground ratio, seismic facies and seismic attribute. It is considered that large-scale nearshore subaqueous fans spread widely at the up thrown block of Shengbei fault with the nature of succession, while turbidite fans developed at the downthrow wall swinging from side to side with frequent migration. Both the nearshore subaqueous fans and the internal sequences themselves show an evident retrogradation depositional trend as the fans moved to the north margin during the deposition period of upper Es4. This suggests an intermitted lake expansion.The fan distribution was determined by the paleo-channel and fault. Wherever there was a channel, there was a fan, to be more specific, large fan responded to large channel and small fan responded to small channel. Moreover, the fault controlled the types of fans. At the up thrown block of Shengbei fault, large-scale nearshore subaqueous fans are developed. At the downthrow wall, the instable sediments at the up thrown block are transported along the steep fault plane, which produce slump turbidite fans.更多还原