非完整井下单井注抽试验数值模拟方法改进

单井注抽试验（SWIW试验）具有成本低、耗时短、易操作等优点，被广泛用于获取野外含水层的弥散度等物理化学参数.然而，井筒附近的流场变化复杂，给模型求解带来不便，尤其是非完整井问题.针对非完整井SWIW试验问题，MODFLOW/MT3DMS软件中包含3种模块:传统WELL模块、高渗透性WELL模块和MNW模块，分别代表 3种常规的数值模拟方法.研究表明现有的这3个模块都存在一些假设条件，野外试验条件可能难以满足.为此，本研究提出一种新的计算方法，即将MNW模块中考虑井中溶质混溶的公式运用到高渗透性WELL模块上，通过一个参数反求案例的分析，证明SWIW试验模拟结果的精度得到提高.基于改进后的模型，探究传统模型中常用的两个假设条件的影响:忽略滤水管空间位置和假设试验过程中流场是稳定.结果表明:（1）非完整井井筒滤水管的位置对浓度结果的影响不可忽略；（2）含水层渗透系数与储水系数的比值较小时，稳定流场这个假设条件会带来误差. 

An Improved Approach in Modeling Injection-Withdraw Test of the Partially Penetrating Well

Single Well Injection-Withdraw (SWIW) test has been widely used to estimate physical and chemical parameters of aquifer due to its advantages of low budget, less time consuming and easy to operate. However, the complex flow fields near the wellbore pose challenges in solving the model of the SWIW test, especially for partially penetrating wells. Currently, three methods included in MODFLOW/MT3DMSwere used to deal with this problem:traditional WELL module, high permeability WELL module and MNW module, which respectively represent three types of commonly used numerical methods. However, it was found that all of these models were based on assumptions which might not be satisfied in the actual applications. In this study, a new method was developed by coupling the MNW module and high permeability WELL module. The case studies demonstrated the accuracy of the new model of the SWIW test. Meanwhile, we employed the new model to investigate two assumptions included in the previous studies, and found that:(1) the influence of the well screen location on the results was not negligible. (2) The assumption of the steady-flow field used in the traditional mathematical model of SWIW will cause non-negligible errors when the ratio of permeability coefficient to storage coefficient is small.