【作者】 韩宗元；

【导师】 苗建宇；

【作者基本信息】 西北大学 ， 地球化学， 2006， 硕士

【摘要】 鄂尔多斯盆地是一个多旋回叠合型盆地,其形成历史早、演化时间长。油气资源非常丰富,油气勘探潜力很大,它已成为我国未来油气勘探最重要的战略地区之一,油气资源分布及其探明程度直接影响着中国石油工业的发展。 运用多学科理论,结合现代测试技术方法,注意宏观与微观相结合,区域资料与单井数据相结合,野外工作与室内工作相结合,对子洲—清涧气区山西组山₂³段及下石盒子组盒₈²段、盒₈¹段储层地质特征进行了分析。研究表明,山西组山₂³段为曲流河三角洲沉积,下石盒子组盒₈²段、盒₈¹段为辫状河三角洲沉积。储集层砂体主要为曲流河三角洲和辫状河三角洲前缘水下分流河道及浅湖滩砂。 研究区山西组山₂³段储集层岩石类型主要为石英砂岩,下石盒子组盒₈¹段岩石类型主要为岩屑砂岩,盒₈²段岩石类型几乎全为岩屑砂岩。山₂³段成分和结构成熟度远远好于盒₈段。经历的成岩作用有机械压实作用、胶结作用、交代作用和溶蚀作用。依据自生矿物组合、分布及形成顺序、粘土矿物转化、孔隙类型及有机质成熟度等指标进行综合分析,认为山西组山₂³段和下石盒子组盒₈²段、盒₈¹段砂岩均已进入晚成岩A亚期,大部分位于晚成岩B期。 地球化学作用是子洲—清涧气区山西组山₂³段和下石盒子组盒₈²段、盒₈¹段成岩作用和孔隙演化重要的控制因素之一。研究区目的层位胶结作用以碳酸盐胶结、硅质胶结及自生黏土矿物胶结为主;交代作用以碳酸盐矿物交代和黏土矿物的交代为主:溶蚀作用以长石的溶蚀和碳酸盐矿物溶蚀为主,压实作用、胶结作用导致孔隙减少,而溶蚀作用和粘土矿物的相互转化等有利于次生孔隙的形成,使物性改善。 次生孔隙的形成主要与碳酸盐矿物、长石的溶蚀及粘土矿物的脱水作用相关,是无机成岩作用和有机热成熟演化产生的CO₂和有机酸溶蚀可溶组分的结果。地下流体作用是必要条件,可溶物质的存在是充分条件。研究区目的层位砂岩中更多还原

【Abstract】 Ordos Basin is a polycyclic superposition basin that is formed in an earlier geological history and has experienced a longer evolution. It possesses abundant oil and gas resources and has bright prospects in oil and gas exploration. It has been becoming one of the important tactical areas in oil and gas exploration in China. The amount of oil-gas resources and the degree which is proven up will directly influence the Chinese petroleum industry.According to theory of multidisciplines, the reservoir characteristics and its preliminary geochemical geneses of the Shan₂³ and He₈ Member in Upper Paleozoic of Zizhou-Qingjian have been studied by means of the combination macroexamination with microexamination and regional with well data as well as the investigation in the field with research indoors. The research as follows that Shan₂³ Member is meandering stream delta facies, Heg and Heg are both braided stream delta facies. Main reservoir bodies include the subaqueous distributary channel sandbodies of the meandering stream delta, braided stream delta front and beach sandstones.The research shows that Shan₂³, main reservoir rock type is quartzose standstone, that of He₈¹, is lithic sandstone and Heg₈², rock type is nearly single lithic sandstone. What’s more, the maturation of composition and texture in Shan₂³ is much better than that of in Heg. Those rocks have experienced diagenesis of mechanical compaction, cementation, metasomasis and dissolution. Based on synthesis analyses of autogenous minerals associations and clay minerals transform and pore types as well as evolution of organic matter etc, the Shan₂³ and Heg Member have already entered into the latediagenesis A subage and most have reached the late diagenesis B subage.Geochemical variation strongly controls the Shan23 and Heg Member’ lithogenesis and pore evolution in Zizhou-Qingjian. Carbonate and siliceous and authigenic clay cementation, carbonate authigenic clay metasomatism, feldspthic and carbonate corrosion are typical and major diagenesis which is great influenced by geochemical variation. The mechanical compaction and cementation are major factors to make reservoir to lose porosity. The dissolution playing an important role to improve reservoir quality is favorable for secondary pores.The formation of secondary pore contributes to feldspthic and carbonate corrosion as well as dehydration reaction of clay mineral, resulting of CO2 and organic acid, providing by inorganic diagenesis and organic thermal mature evolution, corroding soluble components. The dissolution of aluminosilicate and carbonate cement result in organic acid contributed by kerogen before or during it’s mature stage in the source rocks and coal seams nearby, and that of silica is straightly related with alkali water in the pores. Secondary pore in Shan23 are much more than those in Heg and Heg1 is more than Heg2.In another hand, high value of porosity and permeability in Shan23 having rough pore and tunnels is usually closed to the paleochannel sandbodies, high value of porosity with low value of permeability in Heg having slim pore and tunnels represents tight reservoir.On the studying basis of depositional facies belt and sandstone body distribution with the reservoir quality as well as logging, porosity, permeability and so on, the most gas-producting favorable blocks include Yu30-Drill^Yu55-Drill, Yu29-Drill, Yu69-Drill and the more gas-producting favorable blocks include Yu68-Drill Yu48-Drill, Yu40-Drill, Pu2-Drill^Yu69-Drill.更多还原