Modified Archie’s parameters for estimating water saturation for carbonate reservoir in north of Iraq

Abstract Archie’s parameters, cementation factor ( m ), saturation exponent n ) and tortuosity a are general that have effects on water magnitude, due to their sensitivity pores distribution, lithofacies properties wettability, particularly in carbonate reservoirs. Water magnitude has direct effect estimating initial oil-in-place values, inaccuracy its values will lead huge impact errors so it would affect the economics of field management development plans. In this paper, main objective was investigate using conventional modified parameters determination from well log interpretation for Tertiary reservoir Khabaz oil field, heterogenous carbonite north Iraq which affected by different digenesis processes impacted quality. consists five geological units (A, B, C, D E), selected penetrated top at 2200.5 RTKB passed through reached total depth 2348 RTKB. The geothermal gradient 1.12 ℉ per 100 ft, formation resistivity Rw about 0.029 Ω m. first estimated logs Archie model with known , (1, 2 2), respectively, then were determined graphical technique Pickett plot each unit estimate saturation. Finally, results show value more sensitive parameter low-porosity high-clay-volume zone, but less clean high-porosity 18.5% mean than parameters.