In a deep well which can intercept multi-layer aquifer determining aquifer parameters is challenging. Each aquifer layer within a well can have different aquifer properties. They are not necessary to be isotropic media. If this is the case, determination of different aquifer parameters (K, T,S) for each layer is important and logical instead of approximating each parameters as if they are from a single layer. Could any one help me the technique how can i acquire data and calculate aquifer parameters per each aquifer layers?
Well,
Pumping tests can be achieved in each water-bearing horizon, using the drilling isolation technique.
drill- casing, drill-screens(first aquifer)- pumping test-1; then nearby this group,
drill-casing all above, drill- screens(second aquifer)-pumping test-2; again nearby the abovementioned two groups; drill-casing all above, drill- screens(third aquifer)-pumping test-3, and so on.
Regards
There are a number of research papers that consider this question from a steady-state (Sokol, 1963) or Transient (Bennett & Patten, 1960) perspective. However, information is needed for each individual aquifer. Flow logging is the traditional method (e.g., Paillet, 1998, 2001) to measure open hole flow, and from a vertical flow log, vertical flow changes infer horizontal flow (i.e., when the vertical flow changes there must be horizontal flow in or out of the well). It is necessary to conduct 2 flow logs to get transmissivity and head, one under ambient conditions and one under pumping conditions. This being said, open hole flow logs identify the most permeable portions of the hole, and so they can miss the lower magnitude flow zones. Isolating specific zones (i.e., with straddle packers or a borehole seal) will likely identify more of the lower flow zones.
As mentioned before, this is a very interesting topic an quite a difficult task. For starters you have to consider that a well is not the best place to try this, especially if it is an old well, since the conditions within the well would be in equilibrium. Now, as a geophysicist I'm biased to use a well-logging approach, for that your well most have no casing, so I suggest to use a sonic-log tool to assess porosity and electrical-log tool to estimate thickness of each layer, and from there try to estimate your K,T,S. Some tools will work even if your well is cased.
Article Aquifer Parameters Estimation using Well Log and Pumping tes...
this very useful paper , it was published in 2004
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