曲流河点坝型厚油层内部构型及其对剩余油分布的影响

目前中国大部分厚油层类油田已进入高含水开发阶段,水淹严重,剩余油高度分散.为明确曲流河点坝型厚油层的剩余油分布规律及其影响因素,在曲流河点坝内部构型分析的基础上,利用面控制建模方法建立点坝精细构型地质模型;并运用数值模拟方法,采用正交试验与单因素实验相结合,对曲流河点坝型厚油层剩余油分布进行研究.结果表明,曲流河点坝型厚油层剩余油整体分散,局部富集;剩余油主要分布于点坝顶部、侧积层遮挡部位以及井间水驱未波及区域;侧积层倾角、注水方式、侧积面曲率、侧积间距、井网以及侧积层连通性等因素均会对剩余油分布产生重要影响.正交试验结果表明,侧积层倾角越小,连通性越差,侧积间距越大,曲流河点坝型厚油层的开发效果越好.根据曲流河点坝型厚油层剩余油分布特征,可采取在其上部钻水平井、中部转换注水方式和下部调堵油水井的方式进行挖潜.

Study on distribution and influence factors of remaining oil in point bar of meandering river

The thick reservoir in China is in high water cut stage, and is flooded seriously now, in which the remaining oil is greatly dispersed accordingly. In order to clarify the distribution and influence factors of remaining oil in thick reservoir of point bar in meandering river deposit, and based on the internal configuration analysis of point bar, a fine geological model of point bar is constructed, then,the study on point bar reservoir is carried out by means of numerical simulation method and orthogonal experiment with single factor experiments. The results show that, the remaining oil is mainly distributed in the top of point bar, where the lateral accretion sandwich is blocked and the area between the wells where is not flooded; the remaining oil is overall dispersed and locally enriched. The dip, horizontal spacing, connectivity and curvature of the lateral accretion sandwich, water injection mode and well pattern will all have important impact on the distribution of remaining oil. The dip is smaller, the connectivity is poorer, and the horizontal spacing is greater, the development performance of the meandering river point bar reservoir is better. This paper has an important significance on further research of remaining oil distribution and potential tapping measures.