Airlift Testing in Exploration Coreholes

Hydrogeologic studies at mining exploration sites rely on airlift-pumping tests because it is a relatively fast, simple, and accurate method of obtaining hydraulic conductivity values in deep fractured aquifers. A single data set from a typical packer-isolated airlift test can include falling-and rising-head slug sequences, discharge-rate decay from the constant-head pumping, and long-term recovery data. Slug tests need not be instantaneous to be analyzed by the Hvorslev method. Recovery from constant-head pumping can be analyzed by Theis methods, however, casing-storage effects can limit the use of the Theis analysis when the discharge rate is less than about 0.13 L/s (2 gpm).