The Deep Tubewell Drilling Site was located at Phalewas. The GPS Coordinate of the well drilling site is 28°09’21.4″N, 83°38’46.11″E about 790 m SW from Phalewas Policestation .The drilling work was continued smoothly and achieved 132 m of penetration. After this depth, the drilling work was stopped as the well has penetrated sufficient depth.
During the drilling operation; the cutting samples were collected. Representative sample of each layer were collected. The driller has also prepared litholog on the basis of cuttings, nature of progress of the well penetration. According to driller’s lithological log & well penetration rate, the well was designed. After the completion of the drilling work on the basis of aquifer layer presence of the well the screen pipe and casing pipe were lowered. Based on, Driller’s log and comments of main driller on drilling penetration rate, the water bearing zones and their thickness were identified. On the basis of the data, the tube well was designed and well assembly was prepared.
Lithology and Well Design of phalebas DTW
The well development by air compressor and pump test work was done after installation of Tube well. Compressor was used during drilling time and Development of tube well by pump has been carried out immediately after installation of the pipe assembly. The well development has broad objectives:
- To repair damage done to the formaMon (aquifer) by the drilling operation so that the natural hydraulic properties are restored
- To alter the basic physical characteristics of the aquifer near the borehole so that the water will flow more freely to the well.
- The well was developed by Air Compressor to remove soil & fine sand particles contained in the well.
After the water well was developed, pumping test of the well shall be conducted to determine the performance characteristics of a well and hydraulic parameters of the aquifer. From the pumping test data, the principle factors of aquifer performance like Transmissivity and storage coefficient can be calculated. Measurements taken in this pump test were:
- Static Water Level just before the start of pump test
- time since pump started
- pumping rate
- pumping or dynamic water level at various interval during the pumping period
- time of any changes in discharge
- time at which pumping stopped
- water level after the pumping is stopped (recovery) at various interval
The pumping test was carried out by Constant-Rate Test. From the constant rate we obtain value of Transmissivity using semi-log graph (Mme-drawdown graphs) and Cooper-Jacob method .
The pumping test was carried out by Constant-Rate Test. From the constant rate we obtain value of Transmissivity using semi-log graph (Mme-drawdown graphs) and Cooper-Jacob method .