Identification of groundwater-producing fractures by using an electromagnetic borehole flowmeter in monitoring wells on the Oak Ridge Reservation, Oak Ridge, Tennessee

Abstract

This report describes the results of electromagnetic borehole flowmeter surveys taken on the Oak Ridge Reservation (ORR) with an instrument developed by the Engineering Laboratory of Tennessee Valley Authority (TVA). The borehole flowmeter can be used during water injection or pumping to determine the depth, vertical extent, and relative permeability of fractures that are intercepted by the wells. The flowmeter can also be used to measure any natural water flows, up or down an openhole interval, from one permeable fracture to another. These and other data have been used to select screen intervals or sampling ports in newly constructed wells on the ORR, to evaluate the potential for cross-contamination (the flow dissolved pollutants from one level to another in a well or corehole), and to characterize permeable fractures and permeable intervals in wells.