Abstract
Klinkenberg permeability (KI) correction at different overburden pressures and air permeability (Ka) was carried out at the same overburden pressures for one hundred plug samples of 1" and 1.5" diameter from different formations from Sirt Basin of clastic and carbonate reservoirs. The samples were measured using Keyphi instrument, the measurements covered a permeability range of 0.03mD - 600mD. The results showed a strong correlation between the Klinkenberg and air permeabilities for the samples of high permeability values and the effect of slippage is more clear on the low permeability samples (less than 1mD), a composite curve has been established for all the samples in order to investigate the effect of variation in O.B.P on the permeability values.