高含水期油藏开发方式选择及最优方案设计

通过数值模拟,确定了M1油藏高含水期合理的开发方式,在此基础上,利用正交实验设计确定了各井组最优的气水交替注入方案。该方案不仅考虑了CO2注入量、CO2注入速率、水注入速率、CO2段塞数、气水段塞比等因素,还对首段塞与后续段塞比、CO2浓度、焖井时间等因素进行了优化。实验结果表明,首段塞与后续段塞比应在2∶1左右;注入CO2浓度不应低于90%;首段塞合理焖井天数在15 d左右,后续段塞合理焖井天数在7～8 d。将实验结果与水驱方式进行了对比,在开采后期气水交替注入的采油量有了明显的提高,而含水率低于水驱方式,因此CO2气水交替驱技术可以在M1油藏使用。

Selection of High Watery Period Oil Reservoir Development Options and Optimal Option Design

Adopted is the numerical simulation to determine reasonable high watery period M1 oil reservoir development options and applied is the orthogonal experiment design to determine the optimal gas/water alternating injection plans for each well group.In the plans,considered are CO2 injection volume and speed,water injection speed,CO2 slug flow number and gas and slug flow ratio,and optimized are CO2 concentration and well soak time.Experiments show that the first slug flow and subsequent ones shall have a ration of about 2:1,CO2 injection concentration shall not be less than 90 %,the reasonable well soak time for the first slug flow shall be about 15 days and the reasonable well soak time for the subsequent ones shall be about 7 or 8 days.The experimental results show that in comparison with water drive,oil production have been significantly increased by using gas/water alternating injection plan in later development stage and moisture content is less than water drive.Therefore,gas/water alternating injection plan may be applied in M1 oil reservoir development.