乌尔逊凹陷南部南屯组圈闭识别与描述

发布时间：2018-02-24 03:44

本文关键词： 南屯组构造圈闭岩性圈闭有利目标　出处：《东北石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：乌尔逊凹陷南部主要包括乌南次凹、巴彦塔拉构造带两部分。由于受到乌西断裂带的影响,整个乌南次凹呈现出典型的箕状断陷的构造形态,而巴彦塔拉地区为典型的走滑拉分构造。圈闭作为油气聚集的场所,在研究区内对南屯组进行圈闭的识别对勘探开发有着十分重要的意义。在本次研究中,根据层序地层学基本理论,结合测井特征,将南屯组划分出2个3级层序,8个4级层序,以合成地震记录为桥梁,完成了T22反射层、T22-1反射层、T22-2反射层、T23反射层、T23-1反射层、T23-2反射层、T23-3反射层、T23-4反射层、T3反射层等九个反射层的追踪对比解释工作,并在此基础上编制了9个反射层的构造图。以构造图为基础,结合构造地质学相关理论,在南屯组各4级层序顶底面的构造图上完成南屯组的构造圈闭识别工作,总结构造圈闭的分布规律以及南屯组区域构造特征。岩性圈闭的识别工作主要以地震属性分析、地震分频、叠后地震反演以及沉积相研究为基础进行的。首先通过沉积相分析,确定南屯组二段砂岩发育区域沉积背景和沉积模式,然后通过属性分析、地震分频对砂岩进行定性预测,对砂体在平面上的分布形态有一个大致概念。最后应用地球物理反演识别出南屯组二段各个4级层序的砂岩分布特征,确定砂岩的空间展布形态以及砂岩泥岩的接触关系,寻找砂岩尖灭点,对岩性圈闭进行识别与描述,总结岩性圈闭分布的特征。研究表明:研究区南屯组断层分为早期断层与晚期断层两大类,其中早期断层为控陷断层,走向多为近南北向,而晚期断层大多是南屯组沉积时期形成的断裂,主要为北北东走向。南屯组的构造圈闭类型主要是断块以及断鼻两种类型为主。南屯组内部各4级层序的沉积相主要是扇三角洲以及湖泊相沉积环,其中扇三角洲相分布范围广泛,为研究区内储集层砂岩发育优势相。最后依据沉积相图、沿层地震属性图、地震分频沿层水平切片与砂岩厚度图,认为南屯组二段的岩性圈闭类型主要是地层上倾尖灭圈闭。最后综合分析了乌尔逊凹陷南部南屯组地层的生、储、盖等石油地质条件,结合构造圈闭以及岩性圈闭的识别工作,寻找南屯组二段油气聚集有利区,为南屯组下一步的勘探开发提供有利信息。
[Abstract]:The southern part of Wuerxun sag mainly consists of two parts: the subsag of Wunan and the structural belt of Bayan Tara. Due to the influence of the Wuxi fault zone, the whole subsag of Wuerxun presents a typical structural form of dustpan type fault depression. The Bayantala area is a typical strike-slip pull-apart structure. As a place for oil and gas accumulation, the trap identification of Nantun formation in the study area is of great significance for exploration and development. According to the basic theory of sequence stratigraphy and well logging characteristics, the Nantun formation is divided into 2 sequences of magnitude 3 and 8 sequences of magnitude 4. The synthetic seismogram is used as a bridge. T22 reflection layer T22-1 reflection layer T22-2 reflection layer T23-1 reflection layer T23-1 reflection layer T23-2 reflection layer T23-3 reflection layer T23-4 reflection layer T23-4 reflection layer T23-4 reflection layer, T22-2 reflection layer T22-2 reflection layer T23-1 reflection layer T23-1 reflection layer T23-2 reflection layer T23-2 reflection layer T23-3 reflection layer T23-4 reflection layer T23-4 reflection layer and T 3 reflection layer, Based on the structural map, the structural trap identification of Nantun formation is completed on the top and bottom maps of each order sequence of Nantun formation, based on the structural map and the related theory of tectonic geology. The distribution of structural traps and the regional structural characteristics of Nantun formation are summarized. The identification of lithologic traps is mainly based on seismic attribute analysis, seismic frequency division, post-stack seismic inversion and sedimentary facies study. The sedimentary background and sedimentary model of sandstones in the second member of Nantun formation are determined, and then the sandstone is predicted qualitatively by means of attribute analysis and seismic frequency division. There is a general concept of the distribution form of sand body on the plane. Finally, the distribution characteristics of sandstone in each 4 order sequence of the second member of Nantun formation are identified by using geophysical inversion, and the spatial distribution of sandstone and the contact relationship between sandstone and mudstone are determined. In order to identify and describe lithologic traps, the characteristics of lithologic traps distribution are identified and described. The study shows that the faults of Nantun formation in the study area can be divided into two types: early faults and late faults, among which the early faults are controlled subsidence faults. Most of the faults were formed in the sedimentary period of Nantun formation, and most of the late faults were formed in the sedimentary period of Nantun formation. The main structural traps of Nantun formation are fault block and fault nose. The sedimentary facies of each order 4 sequence in Nantun formation are fan delta and lacustrine sedimentary ring. The fan delta facies are widely distributed, which is the dominant facies of sandstone development in the study area. Finally, according to sedimentary facies diagram, seismic attribute map along layer, horizontal slice of seismic frequency along layer and sandstone thickness map, It is considered that the lithologic trap type of the second member of Nantun formation is mainly stratigraphic tipping out trap. Finally, the petroleum geological conditions of the formation of Nantun formation in the south of Wuerxun sag are comprehensively analyzed, combined with the identification of structural traps and lithologic traps. In order to provide favorable information for further exploration and development of Nantun formation, a favorable area for hydrocarbon accumulation in the second stage of Nantun formation is sought.
【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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