分段射孔是一种常用的水平井射孔工艺。由于多个射孔段的存在，使得水平井每个射孔段的产能预测变得十分复杂。用Fourier正弦变换、势的叠加原理、三角函数变换、渐进分析求解了圆形封闭地层水平井三维拟稳态渗流问题，得到了水平井的均匀流量产量模型。通过与直井产能对比，求得水平井稳态当量井径，再利用压降叠加原理建立了分段射孔水平井产能计算方法。研究表明，水平井垂向位置影响当量井径；分段射孔时，相同射孔长度下，端部(趾端,跟端)产量最大，而中部井段产量最小；多个射孔段同时投产时，射孔长度对射孔段产量的影响较射孔间距大。此方法可以用于确定水平井射孔段分段产量。

Segmental perforation is widely used for horizontal wells. However, the flow of fluid in porous media is a complex problem. Using the Fourier transform, principle of potential superposition, trigonometric function transform, asymptotic analyses, a pressure solution of a pseudo steady-state flow model in 3D circular-boxed media has been established. Comparing with the productivity of vertical wells, an equivalence radius model can be obtained. Based on the model, a method of evaluating the productivity of segmental perforation horizontal well is presented by means of principle of superposition. It shows that the equivalence radius is different for various positions of horizontal wells; the output of both ends of horizontal wells is greater than the others under the same length of perforation interval; it is more important to obtain high productivity by increasing the length of perforation interval than enlarging the spacing between perforation intervals. The result of this research can be used to ascertain the yield of each perforated interval.