【作者】 惠宽洋；

【导师】 刘家铎；

【作者基本信息】 成都理工大学 ， 古生物学与地层学， 2005， 博士

【摘要】 本文针对鄂尔多斯盆地塔巴庙地区风化壳岩溶这种非常规油气储层的成因分布特征和隐蔽气藏成藏机理问题，运用多种新理论、新方法和新技术，静态和动态相结合，进行全面系统的成藏地质条件研究，取得了新的重要研究成果和认识。 1．岩溶作用、交代作用和溶蚀作用储层形成具有建设性作用，其中大量次生孔隙的形成分为两个阶段，第一阶段是同生～表生期的古岩溶作用，形成大量溶洞、裂缝和孔隙；第二阶段是晚期成岩的白云岩化作用阶段形成粉晶白云岩储层，其形成机理是成岩晚期深埋藏酸性热水成因。马五5粉晶白云岩化储层是本次研究的第一个重大发现。同时发现的地开石对成岩晚期储层改造和次生孔隙形成具有积极的贡献。 2．充填作用是风化壳储集空间急剧减少的根本原因。研究的第二个重要发现是研究区北部大32井存在大型洞穴充填，大量黑色泥岩和炭屑提供了证据，表明岩溶作用强，具备形成大型孔洞的条件；化学充填包括淡水方解石充填、热水充填和沥青充填；充填作用在早期以洞穴充填和溶蚀充填为主，晚期以自生矿物和沥青充填为特征。 3．第三个重要发现是在已知的两个水平岩溶带的基础上，发现了第三水平洞穴砂砾岩，位于马五5～马五6之间，表明塔巴庙地区存在三期岩溶旋回；岩溶分带划分为地表岩溶带、垂直岩溶带、水平岩溶带和深部岩溶带。 4．古岩溶地貌控制储层分布。采用残余地层厚度法和基准面旋回法恢复加里东期古地貌特征，将研究区划分为岩溶高地、岩溶低地、岩溶脊地和岩溶斜坡。与区域风化壳古地貌特征相吻合。进一步完善和深化了古地貌特征，是本次研究的重要特色。 5．首次利用地震伽玛反演技术对风化壳薄储层进行尝试性预测，是技术方法上的重大突破。实现了马五5灰岩标志层的识别，可以清晰识别风化壳层内储层，预测表明北部是储层有利发育区。 6．首次通过气源地质地球化学研究和对比追踪证明风化壳天然气来源于煤系烃源岩生成的煤成气，具有上生下储的煤系地层含气系统，解决了气藏形成的更多还原

【Abstract】 Based on the application of theories new methords and technologies combined with geological and testing data, the theses mainly deals with the distribution and reservoir mechanics of carbonate rock subtle oil and gas reservoir in Ordos basin, which is developed by the weathering of carbonate during late Ordovician. Synthetically study achievements have been made as follows:1. Constructive diagenesis consists of karstification, replacement, dissolution and recrystallization for the Ordovician carbonate rocks. Secondary porosity formed in two stages, first stage occurred during the penecontemporaneous and epigenesis, when the large number of solution cavity, fractures and solution pores developed; the second stage occurred during late diagenesis, the fine crystalline dolostone reservoir fomed. The formation of intercrystalline pores is due to the hydrothermal water disslution. M₅⁵ fine crystalline dolostone reservoir is firstly recognized in this study. The dickite recognized by SEM contributed lots to the late diagenetic dolostone reservoir.2. Infiltration is the main factor which sharply reduces the space of karst reservoir. The second important discover in this study is that large cavity infiltrated by dark mud and clast of carbide plant in well 32. That shows the strong karstification indicating the existence of cavity forming conditions. Chemical infiltration includes fresh water calcite, hydrothermal material and bitumen. Cavity and dissolution infiltration developed earlier than the infiltration of authigenic minerals and bitumen.更多还原