Application of velocity-deviation log to Reservoir Characterization of Asmari Formation in One of the Iranian Oil Fields

the velocity - deviation log, which is calculated by combining the sonic log with the neutron porosity density log, provides a tool to obtain downhole information on the paramount . Pore type in carbonates. The log can be used to trace the deownhole distribution of diagenetic processes and to estimate trends in permeability. laboratory measurements on carbonate samples expose that sonic velocity is a function not only of total porosity , but also of the paramount pore type. to produce velocity -deviation log, porosity logs were converted to synthetic velocity log using. wyllie equation . the difference between the real velocity calculated from sonic log and synthetic velocity calculated from porosity log, is defined as a velocity -deviation log. deviating to negative or positive values indicate the pore type. zones with small deviations are dominated by interparticle , intercrystalline , or high microporosity. all of these pore type are par-ticularly predominant in a sediment just after deposition, when original grains or micrite are simply packed together.

Keywords:

velocity - deviation , asmari , porosity.