2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 8
Presentation Time: 3:30 PM

Non-Darcian Flow to a Well In Leaky Aquifers


WEN, Zhang, Department of Irrigation and Drainage, College of Water Conservation and Civil Engineering, China Agricultural University, Beijing, 100083, China, HUANG, Guanhua, Department of Irrigation and Drainage, College of Water Conservation and Civil Engineering, and Chinese-Israeli International C, China Agricultural University, Beijing, 100083, China and ZHAN, Hongbin, Department of Geology & Geophysics, Texas A&M University, Mail Stop 3115, College Station, TX 77843, wenzhangcau@gmail.com

In this study, we use a linearization procedure and a finite difference method to solve non-Darcian flow to a well in a leaky aquifer. The leakage effect is considered. Flow in the aquifer is assumed to be non-Darcian and horizontal, whereas flow in the aquitard is assumed to be Darcian and vertical. The Izbash equation is employed to describe the non-Darcian flow. The wellbore storage is also considered in this study. We have compared the results in this study with our previous study in which the leakage was not considered. The comparison between our solutions and Hantush and Jacob (1955) who investigated a similar problem in Darcian flow case to see the non-Darcian effect has also been included. The results indicate the dimensionless drawdown in the aquifer with leakage was less than that without leakage, and the leakage has little effect at early times. The comparison between the results of this study and that of Hantush and Jacob (1955) indicates that the dimensionless drawdown in the aquifer for non-Darcian flow is larger at early times and smaller at late times, than their counterparts for Darcian flow. A larger dimensionless non-Darcian conductivity kD results in a smaller dimensionless drawdown in the aquifer at late times, and leads to a larger dimensionless drawdown in the aquifer at early times. The analysis of the dimensionless drawdown inside the well has also been included in this study when the wellbore storage is considered