期刊名称：Research Journal of Environmental and Earth Sciences
印刷版ISSN：2041-0484
电子版ISSN：2041-0492
出版年度：2012
卷号：4
期号：11
页码：962-981
出版社：Maxwell Science Publications
摘要：A new model for analyzing the hydraulic head in the vicinity of a vertical well in fractured, confined aquifers is presented. This study shows that flow dynamics within the fractured aquifers are more complex than previously believed and the fluid flow behavior can be related to rock deformation through hydraulic conductivity change with fluid withdrawal/injection. This fluid-solid interaction is particularly significant in stress-sensitive, fissured rocks where the rate of withdrawal/injection is high. The model is derived for cubic geometry under hydrostatic confining pressure. The solution, however, can be extended to handle other geometries. Considering the conductivity changes during the life of an aquifer in this study, several findings are drawn: (1) a fully coupled geo mechanics and fluid-flow model is developed to interpret well test data from confined aquifers with linear elastic behavior, (2) for characterizing a fissured, confined aquifer knowing three major parameters may be sufficient, which can be obtained by proper analysis of recovery data, (3) the concept of stress-dependent skin around the wells is discussed and (4) even though the coupled effect may not significantly influence the drawdown/recovery data from a normal (stress-insensitive) aquifer, such a coupled model provides an iterative algorithm to estimate the main fracture parameters, namely fracture porosity, fracture transmissivity, fracture storage capacity ratio and the elasticity parameter. In general, the fluid-solid coupling effects cannot be ignored when analyzing stress-sensitive aquifers unless otherwise it is shown to be negligible.
