A new method determines the skin factor for stimulated wells producing against constant bottomhole pressure.
Drilling, completion, and producing operations may reduce near-wellbore permeability, thereby increasing pressure loss due to skin and correspondingly reducing well productivity. This damage can be eliminated with acidizing or hydraulic fracturing that may improve the well productivity even exceediing production levels corresponding to undamaged conditions. 
To assess the damage, one can use the equations shown in the accompanying equation box.
If cumulative production and time data are available for a well produced against a constant pressure, then one can calculate the skin factor from the flowing time and cumulative production data.
For a well producing against a …