【作者】 王静；

【导师】 钟大康；

【作者基本信息】 中国石油大学(北京) ， 地质学， 2023， 硕士

【摘要】 本文主要以石油地质学、沉积岩石学、油气储层地质学等课程为理论基础,通过野外露头、岩心数据、薄片资料、测井资料与地震数据等资料,利用扫描电镜、阴极发光等技术手段,对川东地区灯影组地层、沉积相与储层等特征等进行了系统研究,取得了以下成果与认识:(1)研究区震旦系灯影组岩性为泥粉晶—细晶白云岩、粉—细晶藻白云岩、砂砾屑白云岩,含少量泥质白云岩、砂质白云岩、硅质白云岩以及泥岩、页岩等,根据岩性及电性特征从下到上可分为灯一段至灯四段。受构造活动影响,在平面上研究区震旦系地层厚度向盆地东南方向减薄。(2)研究区震旦系灯影组主要为碳酸盐岩台地沉积,灯一段、灯二段、灯四段发育局限台地相,灯三段发育混积台地相;通过岩石内藻类、膏质、泥质等沉积相标志,可划分局限台地内颗粒滩、潮坪、泻湖亚相,具体发育有台内藻丘滩、膏质泻湖、泥云坪等微相。(3)研究区震旦系灯影组储层主要发育于灯二段、灯四段;储集岩岩性为粉—细晶藻白云岩、泥粉晶—细晶白云岩、砂砾屑白云岩;储集空间为不整合面附近与古岩溶有关的溶孔溶洞、白云石化作用形成的晶间孔及重结晶作用形成的晶间孔、半充填的小型裂缝等;灯二段平均孔隙度和渗透率分别为1.92%、0.01m D,灯四段平均孔隙度和渗透率分别为0.6%、0.009m D,属于低孔特低渗储层。(4)研究区震旦系灯影组储层的发育受到沉积环境、成岩作用和构造运动影响。藻白云岩、砂砾屑白云岩等形成的台内丘滩(台内藻丘、藻云坪等)是储层形成的物质基础,藻白云岩富含有机质,易被溶蚀,沿藻纹层顺层发育溶蚀孔缝,砂砾屑白云岩多受到白云石化作用、重结晶作用形成白云石晶间孔、砂砾屑粒间孔,储集空间发育;灯二段、灯四段沿不整合面发生表生岩溶作用,使得地层顶部形成溶孔溶洞,垂直向下溶孔规模变小,数量减少;烃类充注在早期充填岩石孔隙避免后期被胶结作用破坏,有利于保存储集空间;以水平拉张为主的桐湾运动形成较多拉张缝,大气淡水沿拉张缝向下溶蚀形成溶缝、溶沟,多期构造运动形成的裂缝有效改善研究区灯影组储层的储集性能,利于油气运移与存储。更多还原

【Abstract】 In this paper,petroleum geology,sedimentary petrology,oil and gas reservoir geology and other courses as the theoretical basis,through the field outcrop,core data,thin section data,logging data and seismic data,using scanning electron microscopy,cathode luminescence and other technical means,the Dengying formation,sedimentary facies and reservoir characteristics in the eastern Sichuan area are systematically studied.The following achievements and understandings have been achieved:(1)The Sinian Dengying Formation in the study area is composed of argillite-fine-grained dolomite,silty-fine-grained algal dolomite,sand-gravel dolomite,with a small amount of argillaceous dolomite,sandy dolomite,siliceous dolomite,mudstone,shale,etc.According to lithology and electrical characteristics,the first member of Dengying Formation,the second member of Dengying Formation,the third member of Dengying Formation and the fourth member of Dengying Formation can be divided from bottom to top.the second member of Dengying Formation and the fourth member of Dengying Formation are rich in algal dolomite,while the third member of Dengying Formation develops argillite and mudstone.Under the influence of tectonic activities,stratum thickness thinned to the southeast of the basin in plane.(2)The Sinian Dengying Formation in the study area is mainly carbonate platform deposition,the first member of Dengying Formation,the second member of Dengying Formation,the fourth member of Dengying Formation developed restricted platform facies,the third member of Dengying Formation developed mixed platform facies;The subfacies of granular beach,tidal flat and lagoon in restricted platform can be divided according to the sedimentary facies markers of algae,paste and mud in rocks.In particular,microfacies such as algal dune beach,paste lagoon and mud cloud flat in platform are developed.(3)The Sinian Dengying Formation reservoir in the study area consists of the second member of Dengying Formation and the fourth member of Dengying Formation;The reservoir rocks are silt-fine-grained algal dolomite,silt-fine-grained dolomite and sand-gravel dolomite.The reservoir space is the karst cave,dolomitization,recrystallization,semi-filled small fractures and so on.The average porosity and permeability of the second member of Dengying Formation were 1.92% and 0.01 m D respectively.The average porosity and permeability of the fourth member of Dengying Formation were 0.6% and 0.009 m D respectively.Dengying Formation reservoir is of low porosity and ultra-low permeability type.(4)The development of Sinian Dengying Formation reservoir in the study area was influenced by sedimentation,diagenesis and tectonic movement.The algal dolostone and sand-gravel dolomite formed the inner platform dune beach(algal dolostone,algal cloud flat,etc.),which is rich in organic matter,is easy to be dissolved.The dissolution pore is developed along the algal laminae.The mud-silt dolostone and sand-gravel dolostone are mainly affected by dolomitization and recrystallization to form dolomite intercrystalline pore and intergranular pore,and the reservoir space develops.Epigenetic karstification occurred along the unconformity surface of the second member of Dengying Formation and the fourth member of Dengying Formation,resulting in the formation of solution pores and caves on the top of the strata,and the scale of vertical downward solution pores became smaller.Hydrocarbon charging can fill pores in the early stage to avoid the damage of cementation in the later stage,which is conducive to the preservation of reservoir space.The horizontal stretching movement in Tongwan formed more Doric tension fractures,and the atmospheric fresh water dissolved downward along the tension fractures to form solutionfractures and solutiongullies.The fractures formed by the multi-stage tectonic movement effectively improved the reservoir performance of the reservoir in the study area,which was conducive to oil and gas migration and storage.更多还原