穿透非均质储层的复杂轨迹井产量计算新方法

解析法和半解析法计算水平井产量的公式一般要求油藏储层均质，且井轨迹平行于油藏边界，难以准确地计算复杂轨迹井的产量。根据井轨迹和储层渗透率把油藏划分为若干区域，不同区域渗透率取值不同，且井轨迹可不平行边界。通过引入点源函数法，基于定压油藏边界建立了非均质性储层复杂轨迹井的产量分段积分相似解，利用Ouyang模型计算了井筒内流动的沿程压力损失。该方法避免了数值模拟中数值弥散的发生，只需输入较少的参数就可以对复杂轨迹井进行快速产能评价。实例计算结果表明：①复杂轨迹井井筒内的流量从指端到跟端逐渐增大；②由于储层的非均质性，各段流量分布并不均匀，渗透率高的部位流量也高；③井筒压降从指端到跟端同样逐渐增大，由于流量分布不均匀，因此不同轨迹段在井筒内压降也不相等。该方法计算结果与Eclipse数模方法一致，表明该方法是可行的。应用该方法计算的油井产量与油田现场生产对比，预测油井产量相对误差小于5%，能满足现场油藏工程研究的需要。

A new method for production calculation of complex trajectory wells in heterogeneous reservoir

Analytical and semi-analytical formulas for production calculation of horizontal wells generally require the reservoirs being homogeneous and well trajectory parallel reservoir boundary,which make them unsuitable for complex trajectory wells.In this paper,the reservoir is divided into several regions based on well trajectory and permeability.Each region has different permeability,and the well trajectory within the region may be unparallel with the boundary.The point source function method is introduced to establish the segmented integral similarity solution for the production of complex-trajectory well in heterogeneous and constant-pressure-boundary reservoir,and the Ouyang model is used to calculate the pressure loss along the wellbore.This method can avoid numerical dispersion in simulation,and provide a fast production evaluation with fewer input parameters.Case study result shows that flow rate in wellbore with complex trajectory increases from toe to heel,the reservoir inflow rate is different in each segment due to reservoir heterogeneity and is high in the high permeability reservoir region,the pressure drop within the wellbore also increases from toe to heel and is different in each wellbore segment due to the uneven distribution of flow rate.The result of this method is consistent with that of Eclipse,confirming its feasibility.In comparison with the metered oil production in field,the calculated production of complex trajectory well has an error of less than 5%,showing that it can satisfy the demand of real-field reservoir engineering research.