利用经典理论模型研究流体性质对岩石地震波速度及阻抗的影响

Research of the effect of fluid properties on seismic-wave velocity and impedance of rocks by classical theoretical models

地震响应的变化源于地层结构和岩石弹性性质的变化,影响岩石弹性性质的因素主要有压力、温度、孔隙度及孔隙形态、流体类型及其饱和度等。根据Biot-Gassmann和Kuster-Toksz理论模型,分析了不同孔隙度条件下流体性质及其饱和度对岩石弹性性质的影响,讨论了2种理论模型预测结果的差异。流体对岩石地震波速度的影响主要与孔隙度大小和孔隙形状有关,纵波阻抗对储层中流体变化最敏感,横波阻抗对流体变化不敏感,通过纵横波阻抗联合应用可以提高对储层流体变化的识别精度。

Seismic response changes along with formation structure and rock elastic properties.There are many factors influencing the rock e-lastic properties,such as pressure,temperature,porosity,pore configuration,fluid type,fluid saturation and so on.Based on the Biot-Gassmann and Kuster-Toksoz theoretical models,the effects of fluid properties and saturation on rock elastic properties were analyzed under different porosity,and the difference between the results predicted by two theoretical models was discussed.The influence of the fluid on rock seismic-wave velocity is related to the value of porosity and the shape of pores.P-wave impedance is the most sensible factor among the fluid change in the reservoirs,but S-wave is not.Combination of P-wave and S-wave impedance may be used to enhance the capability of recognizing the change of reservoir fluid.