薄层底水油藏排水采油技术影响因素研究

Study on influence factors of dewatering oil production in thin reservoir with bottom water

系统研究了油藏地质参数与排采工艺参数对薄层底水油藏排水采油技术的影响,定量分析了各因素的作用机理及影响规律。研究表明,排水采油技术对于垂直水平渗透率比较小、底水能量较弱的薄层底水油藏适用性较强;隔夹层从距离油水界面-7.5~7.5 m变化时,排水采油累计产油量呈现缓慢增加—迅速减少—逐渐增加的变化规律,而累计增油量则呈现缓慢增加—迅速减少—迅速增加—逐渐降低的变化规律;当隔夹层中部位于排水井射孔位置时,隔夹层半径的增加有利于排水采油井控水产油,但位于排水井射孔位置以上时,累计产油量先减少后增加,排水采油增油量不断降低;采油井射孔位置越接近油水界面,排水采油增油量越大,产油量越小;最佳射孔打开程度为50%左右;排水层位距离油水界面不宜太远;排水速度与产液速度并非越大越好。研究结果可为现场合理实施排水采油技术提供参考依据。

This paper systematically studied the factors affecting dewatering oil production in thin reservoir with bottom water and quantitatively analyzed the action mechanism and influence law of each factor.Study shows that the dewatering oil production technology is suitable for the thin reservoir with interlayer,bottom water,small vertical permeability and weak bottom water capacity.When the interlayer changes from below 0.7 m to above 0.7 m of oil-water interface,the cumulative oil production rate for dewatering oil production shows the changing law as increasing slowly,reducing sharply and increasing gradualy.The oil increment shows the changing law as increasing slowly,reducing sharply,increasing sharply and reducing gradualy.When the central position of interlayer is in the perforation position of drainage well,the radius increase of interlayer is suitable for controlling water and producing oil of dewatering oil production well.But when the central position of interlayer is above the perforation position of drainage well,the cumulative oil production rate reduces first,then increases.The oil increment of dewatering oil production reduces continually.The production rate decreases and the oil incremental increases with the perforation position near the oil-water interface.The optimal open degree of perforation is 50%.The drainage position should be near the oil-water interface.Drainage speed and liquid production rate are not the bigger the better.This study can provide some references for the field implementing the dewatering oil production.