Numerical modeling of rising-head permeability tests in monitoring wells after lowering the water level down to the screen
Numerical modeling of rising-head permeability tests in monitoring wells after lowering the water level down to the screen
复制标题
监测井水位降至筛管后升头渗透率测试的数值模拟
DOI：
10.1139/t05-003
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
R. Chapuis
中科院分区：
文献类型：
--
作者：
R. Chapuis
在监测井（MW）中进行升头渗透试验时，降低管道内的水位。如果将其降至筛管，则采收率曲线可能与理论直线不同，从而难以评估平均油田水力导电性。本文给出了考虑饱和和非饱和流动完全方程的这类试验的数值分析（有限元法）。数值计算得到的图形与实际现场试验的图形相似。在aquitard中，如果过滤包是由细砂制成的，细砂通过毛细作用保留水分，则筛管脱水的影响在速度图中几乎不可见，在通常的半测井图中无法检测到。在aquaard中，当滤包在脱水过程中不能通过毛细作用保留水分时，半对数图呈现两条直线部分。流速图是守恒方程的一种表示形式，它有助于区分地下水填满屏幕的早期时间间隔和……
To begin a rising-head permeability test in a monitoring well (MW), the water level is lowered in the pipe. If it is lowered down to the screen, the recovery graph may differ from the theoretical straight line, making it difficult to assess the mean field hydraulic conductivity. A numerical analysis (finite element method) of this type of test, considering the complete equations for saturated and unsaturated flow, is presented. The numerically obtained graphs are similar to those of real field tests. In an aquitard, when the filter pack is made of fine sand, which retains water by capillarity, the screen dewatering influence is hardly visible in the velocity graph and is undetected in the usual semilog graph. In an aquitard, when the filter pack cannot retain water by capillarity during dewatering, the semilog graph presents two straight-line portions. The velocity graph, a representation of the conservation equation, helps to distinguish the early time interval, when the groundwater fills the screen and ...