WELL DEVELOPMENT
- It is a process by which the fine particles are removed from aquifer formation surrounding the strainer pipe of the well.
- Following favourable effects are obtained from well development:
- Specific capacity of the well increases.
- Flow of sand into the well is prevented.
- Life of the well is increased.
The well can be developed by following methods:
(i) by pumping,
(ii) by surging,
(iii) by compressed air,
(iv) by back washing,
(v) by dry ice.
(i) Pumping.
- In this method, pumping of water is done non-continuous, irregularly and at variable rate.
- By this fine material surrounding the well gets agitated and carried out of the well.
(ii) Surging.
- A bailer or hollow surge block is moved up and down in the well briskly.
- By this finer particles are agitated and enter the well from where they are pumped out. Sometimes calgon is also added to well water so as to act as dispersing agent for fine particles.
(iii) Compressed Air.
- In this method compressed air is continuously injected which develops an air lift pump system in the well which carries sand particles with water and are pumped out.
- After developing with compressed air, surging is also done to fully develop the well.
(iv) Back Washing.
- In this method water is forced in the reverse direction by means of compressed air pressure.
- All the sand and clay material which is truck around the strainer is agitated and removed.
(v) Dry Ice Method.
- It is a chemical method in which hydrochloric acid and solid sodium dioxide, known as dry ice is used.
- First of all HCl is poured into the well and well is capped.
- Now compressed air is forced into the well which forces
- the HCl solution into the soil formation.
- Now cap is removed and blocks of solid sodium dioxide (dry ice) are put Into the well.
- Due to sublimation CO2 gas is released and this gas develops a very high pressure in the well.
- When the pressure is released muddy water is automatically thrown out of the well. T
- his method is not used in India.