A Method for the Analysis of Tracer Test Data

Abstract

On the basis of a one-dimensional liquid flow along a horizontal path, theoretical tracerconcentration/time behavior at any given locations along the path are calculated: the parameters used are the distance from the tracer release point and the average flow velocity. These calculations show the relationships between the distance and the tracer arrival time, and between the distance and the peak concentration time. These relationships are then plotted on a group of curves. A simple method, based on these theoretical curves, and field tracer test data showing both the tracer initial returns and its peak concentration times, can be used to estimate the flow velocity and the length of the flow path between a tracer release well and an observation well. This method was tested by comparing the theoretical results with actual field data from two geothermal areas. The results of this comparison show that this method can be successfully used when tracer concentration peaks are clearly recognizable.