非均质性致密砂岩油藏CO_(2)混相驱油井产能预测

Productivity prediction of CO_(2) miscible flooding wells in heterogeneous tight sandstone reservoir

为建立更加符合油藏实际的产能计算方法,分析致密砂岩油藏CO_(2)混相驱油井产能影响因素及规律,基于混相驱机理,考虑平面非均质性、启动压力梯度等因素的影响,建立了五点井网下的CO_(2)混相驱油井产能预测模型。通过对平面非均质性的可微处理,推导了产能方程解析解,并进行了实例模拟计算。模拟结果表明,受混相程度及混相带大小的影响,混相带突破后的产能是突破前的1.6倍;依据储层物性选择合理的注采方式可有效避免产能损失。该产能预测方法为致密砂岩油藏实施CO_(2)混相驱提供了相应技术支撑。

In order to establish a more practical productivity calculation method and analyze the influencing factors and laws of CO_(2) miscible flooding oil well productivity in tight sandstone reservoir,based on the miscible flooding mechanism,considering the influence of plane heterogeneity,start-up pressure gradient and other factors,a CO_(2) miscible flooding oil well productivity prediction model under five-point well pattern is established.Through the differentiable treatment of plane heterogeneity,the analytical solution of productivity equation is derived,and an example is simulated.The simulation results show that the productivity after the breakthrough is 1.6 times higher than that before the breakthrough,which is affected by the degree of miscibility and the size of miscible zone;According to the physical properties of the reservoir,the reasonable injection production mode can effectively avoid the production loss.This productivity prediction method provides technical support for CO_(2) miscible flooding in tight sandstone reservoirs.