苏德尔特油田铜钵庙组—南屯组油层多级次基准面旋回格架中的储层非均质性特征

依据不整合面和沉积作用转换面,可将苏德尔特油田铜钵庙组-南屯组油层划分为3个长期基准面旋回和13个中期旋回,并可进一步将主要含油层Ⅰ、Ⅱ油组划分为26个短期旋回(小层)。油组和中期旋回具有良好的对应关系。在多级次基准面旋回格架中,储层非均质性分布表现出明显的规律性,短期旋回不同的结构样式决定了4种层内物性变化模式;中长期旋回及其位置控制储层层间和平面非均质性,基准面上升早期、下降末期及最低位置时,砂体单层厚度大、连续性强、储层物性好,而基准面上升至高位时,因沉积作用能量减弱而砂体储层物性较差。

Reservoir heterogeneity characteristics in the framework of multi-grade base level cycle of the oil layers of Tongbomiao and Nantun Formations in the Sudeerte Oil Field

According to the characteristics of the unconformity and depositional conversion surface,the oil layers of Tongbomiao and Nantun Formations in the Sudeerte Oil Field are divided into three long-term base level cycles and thirteen medium-term base level cycles,and the main oil formationsⅠand Ⅱ are further divided into twenty six short-term base level cycles(layers).The oil formations are well corresponding to the medium-term cycles.In the framework of the multi-grade base level cycles,the reservoir heterogeneity characteristics show obvious regularity: the structural patterns of different short-term cycles determine the four modes of intralayer physical property changes;the medium cycles and their positions control the interlayer reservoir heterogeneity and the plane reservoir heterogeneity;and in the early period of the base level rise,in the late period of the base level fall and in the lowest position of the base level,the sandstone monolayer has large thickness,good continuity and good reservoir physical properties;in the period of high base level,the sandstone reservoir condition is poor.