Influence of Pump Intake Location on Well Efficiency

Abstract

We tested the influence of pump intake location on well efficiency using three intake locations—one above the screen, as recommended by current well design guidelines, and two in the screen. Testing was done in a semicircular physical model of a well with a screen, casing, and gravel pack. The experiments used three screen slot sizes, two sand sizes, and average screen entrance velocities from 0.18 to 0.55 m/s. For the finer sand, experimental results indicated that placing the pump intake at both positions in the screen increased well efficiency; the lowest intake position was generally the most efficient. For the coarser sand, the lowest intake position was also the most efficient; the intake position above the screen and the higher intake position in the screen produced similar, and lower, well efficiencies. These results indicate that the common practice of placing the pump intake above the screen may lead to less efficient well designs. The physical model also showed that the hydraulic head distribution along the length of the screen is not uniform, but has the lowest head values near the pump intake, suggesting that flow concentrates in this region. The low head values near the intake decreased as the screen slot size decreased or as the flow rate increased.