4.11.4. Air Surging and Pumping This method requires two concentric pipes – the inner pipe known as the air line and the outer one known as the pumping pipe (or eductor pipe). The assembly of these pipes is lowered into the well. In air surging, compressed air is injected through air line into the well to force aerated water up through the annular space between the air line and the pumping pipe. As this aerated water reaches the top of the casing, the air supply is stopped so that aerated water column starts falling. Air-lift pump is used to pump the well periodically to remove the sand brought into the well as a result of air surging. The compressed air produces powerful surging action. This method is used to develop wells in consolidated and unconsolidated formations.
