Evaluation of Slug Tests in Wells Containing a Finite‐Thickness Skin

The effects of a finite‐thickness skin (low‐permeability zone surrounding the well bore face) on the response of slug tests is investigated by using a numerical model and a simple analytical solution. The results show that, for skins of finite thicknesses, estimates of hydraulic conductivity provided by slug tests can be more representative of the skin than of the surrounding formation. When a finite‐thickness skin is present, the slug test response is shifted along the horizontal axis, making estimates of hydraulic conductivity unreliable. This result is different from that obtained by using an analytical solution (Ramey et al., 1975) for a skin of infinitesimal thickness.