塔里木盆地二叠系层序地层学研究

【作者】 张琳婷；

【导师】 郭建华； 何治亮；

【作者基本信息】 中南大学 ， 矿物学、岩石学、矿床学， 2009， 硕士

【摘要】 塔里木盆地蕴藏有丰富的油气资源,目前,已在震旦系、寒武系、奥陶系、志留系、泥盆系、石炭系、三叠系、侏罗系、白垩系、古近系和新近系等十余个层系中发现了工业油气流。由于对塔里木盆地二叠系沉积环境、储层及石油地质条件等研究程度较低等原因,导致二叠系中始终没有大的油气勘探突破。本文以沉积岩石学、层序地层学的基本理论为指导,结合地震、测井资料对二叠系地质背景和区域地层层序、沉积发育特点及沉积相的展布进行了较详细的研究,并在此基础上对二叠系的有利勘探区块提出了具体评价意见。论文对二叠系的岩性、沉积构造、古生物、测井曲线等指相标志进行了综合分析,研究认为塔里木盆地二叠纪包括海相和陆相沉积,盆地西部还广泛发育厚度不等的火山岩。二叠纪的沉积相类型可分为碳酸盐岩台地相、河流相、三角洲相和湖泊相,进一步可细分为12个亚相。通过测井及野外剖面资料的综合分析,塔里木盆地巴楚及塔中地区的二叠系可识别出6个层序边界,除了BJ4为Ⅱ型层序边界外,其它各层序均为Ⅰ型层序边界,并以侵蚀下切为特征。根据6个层序边界可将二叠系划分为5个三级层序,这些三级层序都符合Vail经典层序地层学模式。通过测井资料解释的物性数据统计显示二叠系碎屑岩的平均孔隙度值为6-8%,平均渗透率值为0.06×10-3μm2,储层物性总体较差,属中-差储层。二叠系南闸组是研究区内的好储集层,主要分布在塔西南地区,储层岩性包括白云岩类和颗粒灰岩类。其中,白云岩类孔渗性较好,灰岩中的颗粒灰岩孔渗性相对较差。储层平面展布特点为：最好的Ⅰ类储层发育在泽参1井区,周边分布有Ⅱ类储层,在麦盖提斜坡及曲苦恰克构造带上主要发育着Ⅲ类储层。另外,在玛扎塔格构造带及其北部的和田1-和4井为Ⅲ类储层分布区。通过圈闭落实和成藏条件的综合研究,优选有利目标,有望在这些地区实现二叠系油气勘探的新突破。更多还原

【Abstract】 Plenty of petroleum is enriched in Tarim basin, and industrial oil flow has been found in Cambrian System, Carboniferous System, Triassic System, Jurassic System,Paleogene System and Neogene System, but petroleum exploration has not broken through in Permian System because of lower study level of sedimentary facies, reservoir and petroleum geology. The paper, which has studied geological setting, sequence stratigraphy and sedimentary feature, is guided by primary theories of sedimentary rock and sequence stratigraphy, integrated with seismic data and logging data, and the paper has evaluated favorable exploration area objectively in Permian System.Lithology, sedimentary structures,paleontology and logging data have been comprehensively study in the paper, and it can be gotten that facies comprise marine facies and continental facies and thick volcanic rock in Permian System.The facies can be divided into carbonate platform, fluvial,lacustrine,delta, which can be subdivided into 12 subfacies.Six sequence boundaries can be recognized in Bachu and Tazhong area in Tarim basin in Permian System, based on logging and outcrop data.Except B4 boundary belongs to typeⅡ,the others are typeⅠ,with the feature of incised channels.According to 6 sequence boundaries,5 third-order sequences can be divided in Permian System, and all of sequences correspond with classical sequence stratigraphy pattern of Vail. Statistic data gotten by interpretation of logging data show that average porosity of clastic rock ranges from 6% to 8%,and average permeability is 0.06×10-3μm2,so physical property of clastic rock is poorer, which belongs to middle to poor reservoir. Nanzha formation distributes mainly in southwestern Tarim basin, with reservoirs rock types including dolomite and grain carbonate.Physical property of dolomite presents well, but grain carbonate property doesn’t present well.The two kinds of reservoir can be recognized as good.Based on study, the best reservoir distributes around area of well Zecan 1,and typeⅡreservoir distributes fringe of Zecan 1.typeⅢreservoir distributes mainly on Maigaiti slope and Qukuqiake structural zone,what’s more, typeⅢreservoir also distributes on Mazhatage structure belt and northern area of well Hetian 1 to well He 4.更多还原