Abstract

One of the most important tasks in reservoir engineering is characterizing different parameters of the reservoir. Water saturation is a parameter which helps evaluating the volume of hydrocarbon in reservoirs. Determination of this parameter started from 1942 by integrating some well logs in clean sandstones. After that, many scientists introduced some equations to validate this procedure in shaly sands and carbonates. To treat the problem of dependency of water saturation estimation on core analysis in previous works, other scientists proposed using rock physics and arrived at improved models of water saturation estimation. More recently, interpreters have used seismic attributes to evaluate water saturation values directly or estimating proper rock physical properties such as shale volume which are useful in water saturation estimation process.

Key words: Characterizing, well log, water saturation, rock physics, seismic attribute.