بررسي معادلات تجربي و ارايه يك معادله براي محاسبه ضريب سيمان شدگي در يكي از ميادين كربناته سازند آسماري واقع در جنوب غربي ايران

Investigation of Empirical Equa¬tions for Calculating Cementa¬tion Factor, In Carbonate Asmari Formation; The West Southern Iranian Oil Field

Calculation of water saturation plays a major role in formation evaluation. Archie formula is one of the funda­mental methods for calculating the water saturation of formation which contains laboratory measured param­eters named Archie coefficients. When there is no access to laboratory measurement results, the Archie con­stants are used. Due to the heterogeneity and structural variety in different carbonate rocks, Archie constants lead to so many calculation errors. In this study, Archie coefficients have been determined for Asmari formation carbonate rocks through experiments; then some important empirical equations have been used in order to calculate Archie coefficients and compare them with the measured ones; eventually a relationship has been established between porosity and cementation factors. Results indicate that Borai formula has the best accordance with experimental data; but in order to use its formula, we must swap the coefficients with observed experimental data. Results also suggest that the experi­mental data have coefficient of correlation equaling 76 percent and we will witness better results provided that there are isolate samples with porosity lower than 5 percent.