【摘要】 鄂尔多斯盆地奥陶系马家沟组五段自上而下分为马五1至马五1010个亚段,其中马五1+2、马五4、马五6、马五8、马五10等亚段处于相对海退期,以发育膏盐沉积为特征,马五3、马五5、马五7、马五9等亚段处于相对海进期,以发育灰岩沉积为特征。综合露头剖面、钻井岩心及岩石薄片的观察,结合测井、地震解释及单因素综合方法,在马五段中识别出16种典型的沉积微相序,建立了相应海进期和海退期沉积模式。勾画出古隆起东侧马五段中组合(马五5—马五10亚段)台内颗粒滩分布。恢复了盆地马家沟组五段内10个亚段的岩相古地理。预测了马家沟组上组合(马五1—马五4亚段)风化壳岩溶储层及中组合白云岩储层发育有利相带的平面分布。更多还原

【Abstract】 the Ordovician Majiagou Formation can be divided into six members in Ordos Basin,The fifth member,Majiagou Member-5(Ma-5),can be further divided into ten submembers,including Ma-51 to Ma-510,in which the Ma-51+2,Ma-54,Ma-56,Ma-58 and Ma-510submembers deposited during relative regressions,and the Ma-53,Ma-55,Ma-57 and Ma-59 submembers deposited during relative transgressions.The formers are commonly composed of gypsum and salt while the latters are commonly of limestone.Based on the observation of the outcrops,drill cores and thin sections,as well as well logging and seismic interpretation,16 sedimentary microfacies sequences are identified by the single-factor integrated method and then the associated models of transgression and regression are established.The distribution of intraplatform grain beach is sketched in the Middle Assemblage(Ma-55 to Ma-510) on the east side of paleouplift and 10 Majiagou submembers of lithofacies palaeogeography are reconstructed and mapped.The plane distribution of favorable sediment facies belts is predicted for the weathering-crust karst reservoirs in the Upper Assemblage(Ma-51 to Ma-54) and the dolostone reservoirs in the Middle Assemblage of Majiagou Formation.更多还原