Отправлено: 03.12.15 06:12. Заголовок: Experimental Study of the Effects of IFT and Hysteresis on Resistivity and Capillary Pressure of Car

Experimental Study of the Effects of IFT and Hysteresis on Resistivity and Capillary Pressure of Carbonate Rocks
P. H. Ahmadzadeh,1 M. Masihi,1 A. Al-Ajmi,2 T. Al-Wahaibi,2 and Y. Al-Wahaibi2

Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran,
Iran
Petroleum and Chemical Engineering Department, Sultan Qaboos University, Muscat, Oman
Characterizing the electrical resistance of the formation rock is of great importance in, for example,
interpreting the well log data, calculating the porosity, and water saturation for the formation rocks. The
relation between the resistivity factor and porosity and also between the resistivity index and water
saturation (Archie equation) in the formation rock uses the parameters, such as the cementation factor
and saturation exponent. However, the direct application of Archie equation to carbonate rocks that are
very heterogeneous and mostly oil-wet needs further investigation. In this experimental work, the
effects of overburden pressure, temperature, and interfacial tension on the capillary pressure and
resistivity characteristics during the imbibition and drainage processes are studied. The results showed
a decrease of the saturation exponent when the rock changes from the oil-wet to the water-wet, during
the primary drainage (e.g., from 5.6 to 2.29), imbibition (e.g., from 3.98 to 1.93), and the secondary
drainage (e.g., from 4 to 2.04). As a result, this study improves understanding of the reservoir rock
behavior especially when the enhanced oil recovery processes are studied.