渤海庙西凹陷重点探井古近沉积岩相特征分析

发布时间：2018-03-03 06:22

本文选题：沉积相　切入点：体系域　出处：《东北石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：庙西凹陷位于渤中坳陷东南部,渤中坳陷是渤海湾盆地最大的一个坳陷,根据目前的研究情况,这里是渤海湾盆地的主力生油坳陷之一,曾经发现了好几个特大油气田,如PL19-3油气田和PL25-6油气田。而目前,庙西凹陷的勘探程度还很低,研究程度还不够,所以为了正确认识庙西凹陷古近系的沉积相类型及其时空分布演化规律,更好的指导古近系隐蔽圈闭油气藏的勘探开发,本文运用层序地层学和沉积学原理等相关知识,通过详尽的岩心观察、测井和古生物资料分析,对庙西凹陷的沉积相进行再认识。依据沉积特征,将古近系划分为4个二级层序,7个三级层序。二级层序依次为孔店组、沙四段、沙三段、沙二-东营组,其中沙二-东营组划分为东二、东三、沙一段和沙二段。受物源供应、物源方向和湖平面变化的控制,古近系发育湖泊、扇三角洲和辫状河三角洲三种沉积相,可划分为5个沉积亚相,分别是辫状河三角洲平原、前缘、扇三角洲平原、滨浅湖和深湖-半深湖亚相。在沉积相纵向演化和体系域横向对比研究的基础上,认为庙西凹陷的主要物源来自古庙西河和古旅顺河,从沙河街组至东营组时期,整体表现为湖区范围扩张、湖平面上升的趋势,在东营组二段时期,湖平面达到一个最高值。
[Abstract]:The Miaoxi Depression is located in the southeast of the Bozhong Depression, which is the largest depression in the Bohai Bay Basin. According to current research, this is one of the main oil-producing depression in the Bohai Bay Basin, and several large oil and gas fields have been discovered. For example, PL19-3 oil and gas field and PL25-6 oil and gas field. At present, the exploration degree of Miaoxi sag is still very low and the research degree is not enough. Therefore, in order to correctly understand the sedimentary facies type of Paleogene and its temporal and spatial distribution and evolution law in Miaoxi sag, To better guide the exploration and development of Paleogene subtle traps, this paper applies sequence stratigraphy, sedimentology and other relevant knowledge, through detailed core observation, logging and paleontological data analysis, According to the sedimentary characteristics, Paleogene is divided into four secondary sequences and seven third-order sequences. The second order sequences are Kongdian formation, Sha 4 member, Sha 3 member and Sha Er-Dongying formation. There are three sedimentary facies in the Paleogene, namely, lake, fan delta and braided river delta, which are controlled by the source supply, the direction of the source and the change of lake level. It can be divided into five sedimentary subfacies, namely braided river delta plain, front edge, fan delta plain, shore-shallow lake and deep lacustry-semi-deep lacustrine subfacies. It is considered that the main provenance of the Miaoxi sag comes from the ancient Miao Xihe River and the Gulieshun River. From Shahejie formation to Dongying formation, the whole area of the lake area expands and the lake level rises. In the second stage of the Dongying formation, the lake level reaches a maximum value.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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