A direct benefit of efficient wells is reduced pumping costs. Well efficiency is controlled by several factors, including aquifer, drilling damage, and turbulent-flow losses at or near the well screen. Screen entrance velocity is not a critical design factor if values are less than 2-4 fps (0.6-1.2m/s). For most wells, the required open area of a screen need only be 3-5%. A new method of designing minimum length of well screen based on laminar flow-turbulent flow considerations is presented, along with a simple field test to calculate the efficiency of an existing well or to provide a criterion for termination of development of a newly constructed well.
This paper details specific design considerations that should be taken into account when designing a water production well.