4.11.5. High-Velocity Jetting This method consists of shooting out high-velocity jets of water from a jetting tool to the aquifer through the screen openings. The equipment of this method consists of a jetting tool provided with two or more equally spaced nozzles, high-pressure pump, high-pressure hose and connections, and a water supply source. The forceful action of high-velocity jets loosens the drilling mud and agitates, and rearranges the sand and gravel paritcles around the well. The loosened material is removed by pumping. In this method of development, the entire surface of the screen can be subjected to vigorous jet action by slowly rotating and gradually raising and lowering jetting tool.
This method has the following advantages:
(i) The energy is concentrated over a small area with greater effectiveness. (ii) Every part of the screen can be developed selectively.
(iii) The method is relatively simple.
The method of jetting is particularly successful in developing highly stratified and unconsolidated water-bearing formations.
