Editing Well test (section)

{{short description|Evaluation of how much water can be pumped from a water well}}
{{About|the water well test|the performance testing of oil wells|well test (oil and gas)}}

In [[hydrology]], a '''well test''' is conducted to evaluate the amount of water that can be [[Pump|pumped]] from a particular [[water well]].  More specifically, a well test will allow prediction of the maximum rate at which water can be pumped from a well, and the distance that the [[water level]] in the well will fall for a given pumping rate and duration of pumping. 

'''Well testing''' differs from [[aquifer test]]ing in that the behaviour of the well is primarily of concern in the former, while the characteristics of the [[aquifer]] (the geological formation or unit that supplies water to the well) are quantified in the latter.

When water is pumped from a well the water level in the well falls.  This fall is called [[drawdown (hydrology)|drawdown]].  The amount of water that can be pumped is limited by the drawdown produced.  Typically, drawdown also increases with the length of time that the pumping continues.

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[[Image:SteppedRec.gif|thumb|right|250px|The blue line shows the water level record in a well measured during a stepped-rate well test; the purple line shows a simulation calculated from the derived well equation.  There are three consecutive steps of increasing pumping rate, and then the final (right side) section of the graph records the rise in water level when pumping stops.]] 
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