【作者】 丛宝华；

【导师】 赵俊兴； 黄思静；

【作者基本信息】 成都理工大学 ， 矿物学、岩石学、矿床学， 2011， 硕士

【摘要】 鄂尔多斯盆地苏里格气田东部奥陶系马五段为该区天然气重要产层,对其储层地质特征的详细研究对进一步勘探与开发具有重要的意义。本文以苏里格气田东部马五段为研究对象,在前人研究的基础上,以沉积学、储层地质学理论为指导,通过对18口钻井岩芯的精细描述、大量的岩石薄片鉴定及扫描电镜等资料的分析,结合岩芯孔渗分析数据,对苏里格气田东部马五段沉积微相、成岩作用、储层特征等方面进行了全面深入的研究,取得了以下几个方面的认识:1.据该区岩芯描述及薄片鉴定表明在研究区主要有10种不同的岩性微相组合类型:泥-微晶白云岩、微-粉晶白云岩、微-粉晶灰云岩、粉-细晶云灰岩、泥-微晶灰岩、泥灰岩、泥云岩、石膏岩、膏溶角砾岩以及膏质白云岩。2.通过大量的薄片观察、岩芯分析,结合油田以往的研究资料,认为研究区马五段储层的主要成岩作用类型有白云石化作用、压实作用、压溶作用、重结晶作用、溶蚀作用、去膏化作用、去白云石化作用、黄铁矿化等。表生期的溶蚀作用对马五1-4期储层的最终形成起到至关重要的作用,成岩作用特征可概括为:溶蚀作用最利于储层的发育,准同生白云岩作用未形成有利孔隙,但促进了溶蚀作用的进行;压实、压溶作用均不利于储层的发育。3.马五段的孔隙类型主要有晶间孔、鸟眼孔、膏模孔、晶间溶孔、溶孔、溶蚀缝等,其中溶蚀孔(洞)、缝和晶间孔是研究区最主要的储集空间类型。一般认为特定环境中沉积的粉晶白云岩和含硬石膏结核或柱状晶的粉晶白云岩是储层发育的物质基础,而表生成岩期和埋藏成岩期所形成的次生孔、缝、洞及构造裂隙的发育与保存好坏程度是能否形成良好储层的关键,后期的构造裂缝更是改善了储、渗系统。4.研究区马五1-4分析孔隙度主要分布在0.3～14.4%之间,平均4.9%,渗透率主要分布在0.005～7.240×10-3μm2之间,平均0.379×10-3μm2。可见,研究区属于低渗透储层,其中,马五1~3和马五4~1的储层物性较好。5.在沉积环境、成岩作用、孔隙及储层物性研究的基础上,进行了储层评价,将储层进行了分类:Ⅰ类储层、Ⅱ类储层、Ⅲ类储层和Ⅳ类储层,并在研究区测井解释物性数据基础上指出了有利储层发育部位。更多还原

【Abstract】 The Ma5 setion of Ordovician is the most importaint producing reservoirs in the east Sulige Gas Field, Ordos Basin. It is very important to researeh on reservoir characteristic in order to explore and develop natural gas in this area. The researeh object of this paper is Ma5 section of east Slige Gas Field. Based on previous study,and guided by the theory of sedimentology and reservoir geology, author elaborated the sedimentary microfacies, diagenesis, and reservoir characteristic ect. in this paper, by detailed describing the core 18 wells, identifying rock thin section, cathodoluminescence, SEM obseevation, mercury intrusion analysis, logging, database of core porosity and permeability, ect. There are five views are achieved in this study as following:First, according to core descriptions and thin section identifications, there are 10 Lithology-Micro-Phase association: mud- crystallite dolomite、crystallite- powder crystal dolomite、crystallite- powder crystal limestone dolomite、powder crystal-aplitic dolomite limestone、mud- crystallite limestone、mud limestone、mud dolomite、gpsum、gypsum breccia and gypsum dolomite.Secondly, abundant thin section identification, core ananlasis combining the Gas Field reseach data predicts that the main diagenesis in Ma5 section includes dolomitization, compaction, pressure solution ,recrystallization, dissolution, degypsumization,dedolomitization and pyritization. Supergene dissolution phase take a vital importance in M1—4 section reservoir producing, while penecontemporaneous dolomitization just promote the proceeding without the production of advantage porosity; Compaction and pressure solution are all hurmfull to the reservoir development. Thirdly, porosity in M5 section include intraerystalline pore、birdeye pore、gypsum mould pore、intererystalline solution pore、solution pore and dissolution fractures ect. Among them, intererystalline solution pore and dissolution pore are the main reservoir space. Generally statement indicate that in certain depositional environment, crystal powder dolomite and anhydrite containing nodule or columnar crystal crystal powder dolomite are the material base for reservoir development, while the development and Preservation of secondary pore s, cracks and holes formed in Supergene diagenesis and buried diagenesis phase will be the key part in the good reservoir formation, and also the later structural fracture further perfect the reservoir permeability system.Fourthly, sub layer M5₁³ and M5₄¹ reservoir comparatively good,so as the physical property and gas content, and porosity、permeability and gas content degree of saturation own a well correlationship, among them, porosity and permeability present obvious positive correlation. Reservoir anisotropism totally shows that hyposmosis areas partly own middle and high permeability wells, with obvious difference between layers. Statistic analysis shows that high-yield wells are mostly from sub layer M5₁³ and M5₄¹, besides which own few.Fively, on the basis of sedimentary facies, diagenesis, porosity, and reservoir physical property, this thesis make a reservoir valuation, and also divides the reservoir into four: classⅠ、classeⅡ、classⅢand classⅣ. Then the fine reservoir areas are described.更多还原