The sonic propagation velocity in rock mass is a good kind of information to reflecting the synthetical physical property of rock. The explanation of acoustic log information will based on the experimental study on acoustical parameters and the relationship between acoustical and reservoir parameters. A series of downhole and outcropping rocks was selected to measured their physical property parameters such as porosity、permeability、saturation and the P-wave offset time (Tc) and S-wave offset time (Ts) based on different detector frequency and confining pressure, the result of data analysis showed:(1) Tc decreases with the increasing of water saturation, Tc of fluid saturated samples decreases faster with frequency than that of dry samples.When the gas saturation increases.Tc increases slowly while Ts changes little. The influence of gas can be ignored to the rock samples of low-porosity and low-permeability tight gas zone.(2) Tc increases gradually with the increasing of porosity and permeability, the rangeability is more sensitive in the range of low porosity. (3) The relationship between acoustictime and confining pressure is relevant to the result of lithogenesis such as pore structure、degree of grain cementation consolidated level and so on. Both Tc and Ts decreases with the increasing of confining pressure,and the tendency is obvious in the range of low ressure.
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