Abstract: Incomplete wells have been widely used in practice. For those wells whose filter screen ends are at the middle of the aquifer, they cannot be calculated simply by conventional methods. A simplified calculation method is to divide the flow field near the filter screen into layers based on the horizontal stream line. However, it is very difficult to determine the position of the layering line. Therefore, in this paper, several simplified layering methods of seepage field were proposed, including the modified equal seepage path method which assumes that the upper and lower seepage fields have equal seepage path, the modified equal ratio method which assumes that the ratios of well filter length to aquifer thickness in the upper and lower seepage fields are equal, and the equivalent resistance method developed from the equal ratio method. Based on the above results, an approximate calculation method for incomplete wells with filter screen ends away from the confined aquifer level that was developed to improve Sha’s formula which is superior for its simple-calculation and high-precision. Compared with the finite element analysis, this method is more accurate and more applicable.

Key words: incomplete wells in confined aquifers, layering method of seepage field, approximate calculation, FEM