济阳坳陷沾化凹陷古近系沙河街组二段潜山周缘滩坝及物性特征

以高分辨率层序地层学理论为指导,通过岩心、录井和测井分析,对济阳坳陷沾化凹陷沙二段进行划分和对比。在识别和划分不同沉积相的基础上,结合古地理、古水深、物性和油气显示资料,着重对碎屑岩滩坝和生物滩沉积特征和储集层物性进行分析,结果表明:①生物滩和砂滩分布于平坦、开阔环境中,单层厚度薄,分布面积广;砂坝形成于有一定坡度和地形起伏的环境中,单层厚度大,分布局限。②古地貌和基准面旋回是断陷盆地潜山周缘滩坝储集层物性的主控因素。③潜山西侧生物滩物性最好,面积广、厚度薄,物性最有利;其次为东侧砂坝和砂滩,面积局限,厚度大,物性次之;北侧生物滩和砂滩物性较差,面积较广,厚度较大。

Beach-bar deposition and petrophysical properties around buried hills of the Member 2 of Paleogene Shahejie Formation in Zhanhua Sag, Jiyang Depression

Based on high resolution sequence stratigraphic theories, through the analyses of core, mud logs, logging curves, division and correlation of the Member 2 of Paleogene Shahejie Formation were carried out. On the basis of identifying and classifying different kinds of sedimentary facies, a fine study of sedimentary characteristics and reservoir properties of elastic beach-bar and organic bank has been done, with the data of palaeotopography, palaeobathymetric, and petrophysical properties. The results show: ①Organic banks and sand beaches, lying on a flat wide area, have thin single layers and wide distribution; Sand bars, lying on a slope with a certain angle and rugged terrain area, have thick single layers and narrow distribution. ②Palaeotopography and base level cycles are the controlling factors in beach-bar deposits around buried hills of the basin.③ Western organic banks have the best petrophysical properties, wide distribution and thin thickness. Eastern sand bars and beaches have better petrophysical properties, narrow distribution and large thickness. Northern organic banks and sand-beaches have poor petrophysical properties, wider distribution and larger thickness.