筛套环空砾石层压降的简化计算模型

在砾石充填井筛套环空砾石层的压降计算中 ,将液流简化为单向流或径向流计算得到的压降与实际值相差较大 ,描述这种发散流的Yildiz等人的模型比较复杂 ,且求解困难 ,不便于应用。因此 ,提出一种砾石层压降的简化计算方法 ,即将环空砾石层中的发散流简化为锥形流 ,根据Forchheimer方程导出计算压降的新公式。计算结果表明 ,锥形流模型与Yildiz等人的模型计算结果非常接近 ,并且应用更简便。分析结果还表明 ,油井产量以及射孔孔径和孔密度是影响砾石层压降的重要因素。

A SIMPLIFIED METHOD FOR PREDICTING PRESSURE DROP ACROSS GRAVEL PACK

In the prediction of the pressure drop across the gravel pack, the flow across the gravel pack is simplified as linear flow or radius flow for a method in common use. In fact, this method leads to unreasonable result. Yildiz and Langlinais' model can describe the divergence flow accurately, however it is very complicated and not convenient to use. In this work, a new model is evolved. The irregular divergence flow is simplified as cone shaped divergence flow. A new formula for predicting the pressure drop is obtained by using Forchheimer equation. The result of the cone shaped model is in accordence with that of Yildiz and Langlinais' model well. The flow rate, perforation radius and shot density are the key parameters influencing the pressure drop across gravel pack.