VELOCITIES OF COMPRESSIONAL AND SHEAR WAVES IN LIMESTONES AND DOLOMITES IN A GAS FIELD OF SW IRAN

摘要

Carbonates are the second important lithologies, after silicates, in petroleum reserves. Using three wells and DSI tools in one of the gas reservoirs in the Persian Gulf, Iran, four equations between compressional and shear wave velocities have been determined for limestones and dolomites. Then, these relationships have been compared with Castagna's relationships. It is concluded that Castagna's relationships estimated for Vs are less than the actual values in limestones and dolomites in the area of study. Using different crossplots, the gas and dolomitization effects on seismic velocities are studied. Consequently, understanding the gas and dolomitization effects make it possible to separate gas-saturated zones from water-saturated, and dolomites from limestones.