Gaining and losing sections of horizontal wells

The flux along a horizontal well in uniform flow is examined using an analytic three-dimensional, steady model. Wells with uniform head and low pumping rates have gaining sections along which water enters the well and losing sections along which water exits. Such a well may provide a conduit for contaminated groundwater to be drawn into the well, conveyed a large distance, and injected into an uncontaminated region of an aquifer. Dimensionless ratios of the well's length L and radius R, aquifer thickness H, and uniform flow rate U are developed to quantify the minimum pumping rate Q(min) at which no losing section occurs. The ratio Q(min)/(ULH) is presented as a nomograph using R/H and L/H for placement parallel to flow and is 6 piR/H for placement perpendicular to flow, and,a parabolic relationship between these limiting cases is developed for placement oblique to flow. Capture zone geometry is quantified using Q(min)/(ULH).