水平井与非均质盒式油藏耦合模型

A coupling model for horizontal well in heterogeneous box-shaped reservoir

运用Green函数和Newman积原理,建立盒式油藏水平井产量计算模型.模型考虑井筒内的沿程摩擦阻力和加速度压力损失,引入拟表皮系数表征储层非均质性造成的物性差异.实例计算结果表明,该模型与有限差分数值模拟模型计算结果吻合较好,证实了该方法的可靠性;储层非均质性和沿程压降对水平井产量剖面影响较大,渗透率高的区域,流入量较大;在早期,原油的流动为非稳态时,井筒压降对计算结果影响很大,当水平井较长时,井筒压降对产量影响不可忽略;由于井筒流量从趾端到跟端逐渐增加,井筒压降逐渐增大.

Based on Green＇s function and the Newman product principle,we present a model to calculate horizontal well deliverability in a box-shaped reservoir. In this model,we take into account the friction along the wellbore and acceleration pressure loss,and introduce a pseudo-skin factor to represent the reservoir property differences due to reservoir heterogeneity. The result accords with that of the finite difference numerical simulation model,which further confirms the reliability of our method. Simulation results show that reservoir heterogeneity and pressure drops along the horizontal wellbore have significant impact on the flow rate distribution. The higher the permeability is,the greater the inflow. At the early transient state,the oil flow is unstable,and the wellbore pressure drop has a great effect on the flow rate. When the horizontal well is long,the influence of wellbore pressure drop on production is non-negligible. Because of the increment of flow rate from the toe to the heel of the wellbore,the wellbore pressure drop gradually increases.