Measurement of Hydraulic Conductivity Along the Vertical Direction in the Puli Basin
Date Issued
2010
Date
2010
Author(s)
Chen, Po-Jui
Abstract
The permeability of the layer is an important parameter for groundwater research and engineering application. Although one can use pumping-test to measure average hydraulic conductivity of aquifer, one cannot obtain the permeability changes of layers. However, it is difficult to operate double packer slug test and this test is lack of accuracy. The research is measuring the permeability changes of layers on the vertical direction inside the boreholes through heat-pulse flowmeter, therefore we could obtain the data for the permeability of the aquifer changes on the vertical direction.
Due to the difference of well diameters and the amount of pump water, it will cause error when measuring through flowmeter. When Reynolds number of the fluid is bigger than 2100, the flow will enter the turbulent flow status; the fluid will be not only moving forward, but also breaking into eddies and causes the measurement result larger than the reality. Measurement result is affected by the geometric shapes of flowmeter and natural convections, we have to leverage calibration formulas to adjust the measurement results. The calibration formulas would vary by different sizes of well diameters.
The study has been conducted with two wells with diameter as 8 inches but different depths to reflect the water level changes of first and second aquifer. We first pumped water at the top of the well and generated a stable upward flow, and then used heat-pulse flowmeter to measure the flow speed on the vertical direction for the two wells. We recorded the permeability of the layer changes as the depth changed. By using the calibration formula, we could correct the error caused by the turbulent flow when pumping. This has been compared with the stratigraphic column and natural gama and showed great result. Leveraging pumping water data from Central Geological Survey MOEA, we could calculate its continuous changes of hydraulic conductivity on the vertical direction. The result showed that major high permeability section of first aquifer is around below 15.50 meter and the major high permeability of second aquifer is around below 40.75 meter. Although the lithology changes of aquifer is not significant, the hydraulic conductivity of high permeability sections could be as high as 4.5 times of the average hydraulic conductivity of overall aquifer.
Subjects
Heat-pulse Flowmeter
Hydraulic Conductivity
Aquifer
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-99-R96224206-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):56eca3c780c73695ad0cbf570626d412