鄂尔多斯盆地白垩系洛河组至环河华池组砂体展布规律研究

鄂尔多斯盆地洛河组和环河华池组砂岩是白垩系两套重要的含水岩组。通过区域构造背景确定下白垩统地层分布范围,结合沉积相和盆地演化特征分析不同组岩性的发育和分布形态,并利用盆地内丰富的测井资料信息,进行砂体厚度统计。总结出白垩系洛河组砂岩为风成沉积,产状稳定、覆盖面广;环河华池组砂岩由三角洲水下分流河道及滨浅湖滩坝相长石石英细砂岩组成,砂体分布位置以及厚度变化规律有一定的继承性。

SANDSTONE DISTRlBUTION OF THE CRETACEOUS LUOHE FORMATION To THE HUANHE-HUACHI FORMATION IN THE ORDOS BASIN

Sandstones of the Cretaceous Luohe and Huanhe-Huachi formations are important water-bearing formations in the Ordos Basin.The spatial distribution of lower Cretaceous successions has been characterized through regional geological survey.We also analyzed the development of formation rocks and their spatial distribution on the basis of sedimentary facies and basin evolution.In addition,we analyzed the variation of sandstone thickness using well log data in the basin.We conclude that the Luohe sandstones are eolian deposits and they are consistently distributed in a wide area in the Ordos Basin.Sandstones of the Huanhe-Huachi Formation consist of feldspar-quartz fine sands of bar and distributary channel facies,and their spatial distribution and thickness variation show inheritance from underlying successions.