摘要
对于无(弱)水力联系的多含水层,混合井改变了含水层的结构,通过井筒将无(弱)水力联系的含水层联通。对于大区域井流问题数值模拟,MODFLOW中显式流量分配法和"High Kv in Wellblock"法的假设条件都很难得到满足,将两者耦合起来拓展其适用范围。采用质量守恒定理和Darcy定律计算井网格的平均等效渗透系数,结合显式流量分配法模拟混合井流问题。最后,通过两个典型算例来验证该方法的合理性,其中一个算例是非完整井穿透相邻的两个含水层,另一个算例是完整井穿透两个含水层,且中间有隔水层。将耦合法的计算结果与显式流量分配法对比,结果表明:只有在第一个例子中当水流达到稳定时,两种方法的计算结果几乎相同,且井网格的水头差很小;而其它情况两者的差别很明显,且采用流量分配法计算井网格的水头差大于耦合法计算井网格的水头差。根据Neville等的相关结论可知采用耦合法对于文中的两个例子都比较合理。
For a multiaquifer system where there is aquitard or aquiclude,multiaquifer wells change the physical system of a aquifer by establishing direct hydraulic links between units that are otherwise isolated. Therefore,how to establish the mathematic model is the one of the key research problems. For the large scale simulation,the hypothesis of discharge allocation method and ＂High Kv in Wellblock＂ method in MODFLOW can not be satisfied. Therefore two approaches are coupled to enlarge the extent of application. The average equivalent hydraulic conductivities of well blocks are calculated according to mass balance and Darcy＇s law. The discharge allocation method is combined to simulate the multiaquifer well. Two typical examples are also taken to confirm the advantage of the improved approach. For the first example,the well partially penetrates two adjacent layer aquifers whose conductivities are not the same. For the second one,the well fully penetrates two layer aquifers which are divided by the aquifuge. Through comparing the heads calculated by the improved method with the discharge allocation method,the results show that the improved approach is almost the same with the discharge allocation method just when the flow is steady for the first example,and the head difference along the well blocks is almost zero. However,they are significantly different for the other cases. According to Neville,the improve approach is more reasonable for both of the examples.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2010年第3期23-26,73,共5页
Hydrogeology & Engineering Geology
基金
长江中游城市群地质环境调查信息系统和四维地质填图平台建设方法研究(1212010914007)
