| dc.description.abstract | At the research well field of National Central University, the borehole camera images indict that the dip angle of the fractured zone can be as large as 30-60 degree. Such a large dip angle causes a regional flow in the fractured zone and renders the flow field of a pumping test to be radially asymmetric, where the pressure response in the down-gradient and up-gradient of the pumping well is different and a capture zone effect exists in the neighborhood of the pumping well. All the well hydraulics models currently available neglect the dip angle effect. To incorporate the dip angle effect, this project develops a new double-porosity pumping test model, where the matrix flow between the rock matrix and the fractured zone is modeled using the lumped-parameter approach. In the new model, according to the empirical parameters which can be used to predict the limit of the dip angle effect. The dip angle effect is negligible if the dip angle is less than the limit, the field data analysis can using the horizontal fracture model. Otherwise, in the effective situation, the position of the pumping well, observation well and fracture formation strike also need to be considered in. When modeling the pumping test, if observation well and pumping well that are located along the dip angle direction, the horizontal fracture model result of the hydraulic conductivity of the fracture K_f is larger 100 times than the dip angle effect fracture model. If observation well and pumping well that are located along the direction about orthogonal to the dip angle, then the K_f will larger 10-20 times than the dip angle effect fracture model. In addition, the dip angle does not affect the lumped parameter because the pressure head of the fractured zone is radial distribution, both upstream and downstream distribution is effect by the uniform flow only. A 25-hour constant-rate pumping test (40 l/ min) had been conducted from 2014/01/03 to 01/06 in the research well field. The dip angle is 30 degree for the fractured zone, running north to south. The thickness of the fracture zone is about 0.5 meters. The observation well locates about 5 meters from the pumping well. The field data analysis also confirms the theoretical analysis results of the dip angle effect. In this project, we think the dip angle is needed to consider during the pumping test. | en_US |