Characterization of well skin using buildup test and radon as a tracer

Abstract Pressure buildup tests are often used to determine the reservoir permeability and skin factor to quantify formation damage. However, no quantitative method is currently available for calculating the reduced permeability of the skin zone. With the help of radon measurements during the flow period preceding the buildup test, it is possible to calculate both the radius and the altered permeability in the damaged zone based on a radial composite model.