【作者】 陈兆荣；

【导师】 侯明才；

【作者基本信息】 成都理工大学 ， 沉积学， 2009， 硕士

【摘要】 鄂尔多斯盆地苏里格气田北部盒8和山1段为该区天然气主力产层之一,对其储层特征的详细研究对进一步勘探与开发具有重要的意义。本文以鄂尔多斯盆地苏里格气田北部盒8和山1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20余口钻井岩芯的精细描述、大量的岩石薄片鉴定及阴极发光、扫描电镜、压汞分析等资料的分析,结合测井、岩芯孔渗分析数据,对苏里格气田北部盒8和山1段成岩作用、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.根据572个岩石样品的碎屑成分含量统计,采用三角分类图投点定名原则,按岩石组分中碎屑(Q、F、R)成分及含量不同,研究区盒8段数据点主要落在石英砂岩和岩屑石英砂岩区,含量分别是19.74%和67.85%,岩屑砂岩相对较少,占12.41%;而山1层位数据点主要落在岩屑石英砂岩区,占59.32%,其次落在岩屑砂岩占34.46 %,石英砂岩含量最少,占6.22%。2.研究区储层的成岩作用研究表明,破坏性成岩作用主要为压实作用、胶结作用、石英次生加大作用和自生矿物充填作用等,储集砂岩基本上都属于中—强压实强度;建设性成岩作用主要有交代和蚀变作用、溶蚀作用和破裂作用等。3.研究区内储集砂岩的主要孔隙类型有:原生粒间孔、溶蚀粒间孔,粒内溶孔、微孔和破裂缝;按铸体薄片镜下观察孔隙类型、物性特征和毛细管压力曲线和孔隙结构参数特征,可将苏里格北部山1、盒8段砂岩储层的储集岩主要划分:中、小孔-微喉组合的孔隙型储层、中、小孔-细微喉组合的孔隙型储层和微孔-微喉型组合的孔隙型储层,孔喉关系以中、小孔-微喉组合为主。4.通过对苏里格北部的苏44井和统5井等89口井的9511块砂岩样品物性数据进行统计分析表明:研究区砂岩储层主要属于特低孔低渗储层,次为低孔低渗储层,少量低孔特低渗储层、特低孔特低渗储层和中孔-中、高渗储层。岩心测定和测井解释的孔隙度与渗透率相关性分析表明,苏里格北部地区渗透率均与孔隙度呈明显的正相关,说明渗透率的变化主要受孔隙发育程度的控制,孔隙度越好,渗透率越好,显示出孔隙型储层的特征。在辫状河中,心滩亚相的物性最好,洪泛平原的物性相对要差;在曲流河中,河床滞留沉积和边滩物性最好,天然堤次之,河漫滩和河漫湖泊的物性最差。5.研究区砂体分布不均匀,各井钻遇砂体层数不一,且厚度不均,因此研究区山1～盒8上段储层的小层规模储层非均质性较强;研究区渗透率的韵律性主要表现有正韵律型、反韵律型、均质型、复合型和随机型等5种类型,其中复合韵律是主要类型,正复合韵律型最常见;砂体渗透率的平面非均质性非常严重,其中盒8上段的渗透率平面非均质性最为严重,其次是盒8下段,再次山1段;通过变异系数、突进系数和渗透率级差三项标准来评价,无论利用是岩心测定数据还是测井解释的结果,都表明研究区山1～盒8上段砂岩储层的非均质性较强。6.在孔隙类型、成岩作用、储层特征及分类评价基础上,综合分析沉积微相、有效厚度、孔隙度、渗透率等因素,共划分出四类利储层:其中Ⅰ类为有利的储层,Ⅱ类为较有利储层,Ⅲ类为中等储层,Ⅳ类为差的储层。据此标准,对苏里格北部气田山1、盒8段储层进行了有利区筛选,其中有利勘探区主要分布在河道砂体沉积范围内,其中为Ⅰ类(有利区)和Ⅱ类(较有利区)应该是下一步勘探的重点地区。更多还原

【Abstract】 the 8th member of xiashihezi formation and the first member of shanxi formation are the main gas-producing interval in the North Sulige gas field in Ordos Basin, it is vital significant to detailed research on its reservoir characteristics for the next exploration and development. The 8th member of xiashihezi formation and the first member of shanxi formation of north Sulige gas field in Ordos Basin are the main research object of this thesis. Based on predecessor’s achievements, taking the theory of sedimentology and reservoir geology as a guide, by means of detailed observation and description of over 20 wells, analysis of quantity of thin section, cathodeluminescence, scanning electron microscope and date of mercury penetration, combined with analysis of logging, pore and permeability of core, diagenesis and reservoir characteristic of the 8th member of xiashihezi formation and the first member of shanxi formation of Sulige gas field were comprehensively researched, and several recognitions were obtained as follow.1. According to the clastic constituents statistics of 572 rock samples, using the principle of naming by triangle classification chart, in accordance with the difference of the clast (Q, F, R) constituents and content. The data points of He 8 member are mainly in area of quartz sandstone and debris quartz sandstone with the content of 19.74% and 68.75% separately, and the debris sandstone is relative few, which accounts for 12.41%. But the data points of Shan 1 member are mainly in area of debris quartz sandstone which accounts for 59.32%, and the secondly in area of l debris quartz sandstone which accounts for 34.46%, the quartz sandstone content was least, accounts for 6.22%.2. The study of the reservoir diagenesis showed that the destructive diagenesis of the sandstone in study area mainly are compaction, cementation, secondary outgrowth cementation and filling of authigenic mineral. The compaction of sandstone was mainly middle to deep. The constructive diagenesis mainly comprised metasomatism, alteration, dissolution and rupture.3. The pore types of the sandstone of reservoir in study area comprised primary intergranular pores, intergranular corrosion pores, dissolution pores, micro-pores and cracks. By the observation of pore types of thin sections, characteristics, capillary pressure curve, parameters of pore structure, the reservoir of Shan 1, He 8 in the north Sulige can be divided into reservoir of combination of medium to micro pore throat, reservoir of combination of medium, small-tiny pore throat, reservoir of combination of porous and micro pore throat. The main type of pore throat is medium or small-tiny.4. The statistical analysis to properties of 9511 sandstone samples from 89 wells in north Sulige, which include well Su 44 and well Tong 5, indicate that sandstone reservoir of study area mainly are especially low porosity and low permeability ones, secondarily are low porosity and low permeability ones, and few low porosity and low permeability, ones of especially low porosity and low permeability and middle porosity-middle permeability. Porosity and permeability relevance analysis from core sample determination and well logging interpretation indicated that permeability is positive correlation with the porosity in north Sulige, which manifested that permeability change was controlled by porosity, the porosity was better, the permeability was better, that is the characteristic of pore reservoir. In braided river, the properties of channel bar is best, the properties of flood plain is relatively worse; In meandering river, the properties of riverbed lag sediment and point bar is best, the properties of natural levee is secondly best, the properties of washland and flood lake is worst.5. The distribution of sandbody in study area was asymmetry, the layer of sandbody in different well was not the same, and the thickness was distinct, therefore the reservoir heterogeneity of thin interval of Shan 1 to upper He 8 member was very obvious in research area. The rhythmicities of permeability mainly are positive rhythm, inverted rhythm, isotropic, composite and stochastic, the composite rhythm is the predominant type, and the positive rhythm is most common. The areal heterogeneity of sandbody permeability is very serious. Upper He 8 member was most serious, the second was lower He 8 member and then was Shan 1 member. Evaluated by the index of variation coefficient, mutation coefficient and permeability difference,no matter by the result of rock core determination data or by logging interpretation, they both indicated that the heterogeneity of sandstone reservoir of Shan 1 member and He 8 member is relatively obvious.6. Based on of pore type, diagenesis, reservoir characteristic and classification evaluation, comprehensive analysis of sedimentary microfacies, effective thickness, porosity, permeability, it can be divided into four kinds of favorable reservoir, the typeⅠwas the favorable reservoir, the typeⅡwas relatively favorable reservoir, the typeⅢwas normal reservoir, the typeⅣwas bad reservoir. According to this standard, the favorable areas of He 8 member in the north Sulige gas filed were filtered, the favorable area mainly distributed in the channel sandbody, the favorable typeⅠand relatively favorable area typeⅡcould be the key area for the next exploration.更多还原