Pumping tests for water well projects: assessment of aquifer characteristic and water well capacity
Pumping test is a method of measuring the flow of water which is based on observations of continuity water sources and the availability of water from the source itself. Pumping test involves pumping from a test well at a controlled rate and monitoring the flow rate from the well. The aquifer parameters that can be determined include transmissivity (T), hydraulic conductivity (K), and storativity (S). Well performance is determined using step drawdown test. Well performance that can be measured are coefficient of aquifer loss and well loss, well efficiency, specific capacity, well development factor, and optimum pumping rate.
Several possibilities of measuring conditions debits by pumping test include:
- If the comparison of these two conditions (the rate of water drop at the time of pumping against rate of rise of water during recovery) is 1 then source debit = water debit pump discharge (pump output).
- If the rate of water drop during pumping is greater than the rate of rise in water during recovery, it means that the source debit is smaller than the pump (output) debit.
- If the rate of decrease in surface water during pumping is smaller than the rate of increase in surface water during recovery it means that the source debit is larger than the pump (output) debit.
Pumping Test Information and Diclaimer : The flow test completed is not considered accurate unless the contractor uses an actual submersible pump to complete the real pumping test. In most cases. A water well often experiences a notable improvement in flow over the first few weeks of use. This improvement can and should be sped up by developing the well before it’s put into service. After the well is properly developed or after a few weeks of use, a pump test should be completed. This pump test will be a much more accurate assessment of the flow than the initial flow test completed by the driller
Ultrasonic Flowmeter for Water Well Pumping Test
SUPRA uses the ultrasonic non-invasive flowmeter for pumping test. This involves sending and receiving ultrasonic pulses from a pair of sensors and examining the time difference in the signal. This device uses clamp-on transducers that are mounted externally on the surface of the pipe and which generate pulses that pass through the pipe wall. The flowing liquid with in causes time differences in the ultrasonic signals, which are then evaluated by the flowmeter to produce an accurate flow measurement.
Submersible Pump Selection
For each pump, issues to evaluate include the initial cost, cost of installation, cost of operation, cost of maintenance, and expected equipment life. Proper selection of system components can ensure system performance, but changing conditions sometimes justify altering or reselecting components to maintain economical operation. The range of expected operating conditions must be checked against the pump manufacturers’ information to ensure reliable operation, including the ambient air and water temperature ranges, pressures, flow, corrosive and abrasive factors, power supply variation, duty cycle, and protective devices. The pump must be installed according to the manufacturer’s instructions.
Continuous operation of a pump is generally preferable to intermittent operation, but varying water demand usually requires some combination of off and on time. For improved well performance and pump life, system components and storage capacity should be designed to minimize the number of pump starts and stops per day. At the same time, the pump must be sized and set so that it will never run for even a few minutes at “no delivery”,as this will cause damage to the pump bearings by the overheating and failure of the submersible motor. If the well drawdown or the delivery system causes the pump to run at little or no delivery, protection should be provided to the pump. This protection could include a well-level switch that would shut off the pump or sound an alarm if the flow or water level dropped below a safe minimum level. Routine maintenance is often specified by the manufacturer and will include greasing bearings, polarity checks, and alignment checks.
The costs for a submersible pump depend on setting depth, required head and capacity, corrosion resistance, and other factors. Operating costs will depend on motor efficiency, column bearing, hydraulic losses, cable losses, setting depth, and similar factors. A thorough analysis of all factors should be performed to compare surface and submersible motor-driven deep-well pumps for a specific installation. We’ll help you configure high-quality and high-efficiency submersible pump systems optimally for your water supply, hold technical training courses and analyze/repair your submersible pumps. Our pump engineer also offer you a wide range of services by assisting Factory Acceptance Test and Site Acceptance Test for submersible pumps, cooperating with our calibrating pump test services. As well as releasing Certificate of Manufacture from the submersible pump manufactur. By providing international warranty and technical assistance from submersible pump manufacture, we ensure high quality services for our clients