Abstract: Taking the No.3⁴ layer in the second member of Shahejie Formation in Shengtuo Oilfield as an example,the stochastic modeling for spatial distribution of fluvial facies architecture was studied to investigate the remaining oil distribution rules.Seven coring holes were analyzed.Considering many factors such as lithology,sediment feature and electrical feature,nine lithofacies types,seven rank interfaces and seven architectural elements were established by lots of log data.A 3D distribution model for architectural element was developed with the sequential indicator simulation method.The model analysis revealed that the rate of channel charge and channel bar reached 63.1%.The natural levee accounted for 10.6%,and the crevasse splay,floodplain fine grain,channel lag deposit and interlayer accounted for 8.9%,8.1%,4.9% and 4.4%,respectively. Taking architectural element and remaining oil saturation model into a comprehensive element,the remaining oil was forecasted.Then,the same method was used for remaining oil distribution study of multi-architectural-elements combination.The remaining oil saturations of four blocks are above 50%.These areas would have rich remaining oil.

Key words: Shengtuo Oilfield, fluvial facies, architectural element analysis, spatial distribution model, remaining oil distribution, stochastic modeling

摘要： 以胜坨油田二区沙二段3⁴层为例,对河流相建筑结构空间分布进行了随机建模,研究了剩余油分布规律。对7口取心井进行了观察和分析,利用密井网条件下组合测井资料,综合考虑岩性、沉积特征、电性特征等因素,共划分出9种岩相类型、7级界面和7种结构单元。应用优选序贯指示模拟方法,建立了结构单元三维空间分布模型。检验结果表明,该模型具有较高的准确性。用该模型确定了结构单元,河道充填沉积和心滩为63.1%,天然堤为10.6%,决口扇为8.9%,洪泛平原细粒为8.1%,河道滞留沉积和落淤层分别为4.9%和4.4%。对各个结构单元和多个结构单元组合进行分析及与剩余油饱和度模型进行叠合分析发现,4个井区的剩余油饱和度均在50%以上,具有较大的增产潜力。

关键词: 胜坨油田, 河流相, 结构单元, 空间分布模型, 剩余油分布, 随机模拟