储层条件下砂岩纵波和横波速度的理论计算

The estimation of P and S-wave velocities in sandstone under in-situ conditions

1. 大庆石油学院，黑龙江安达151400;2. 中国地质大学，北京100083

1. Daqing Institute of Petroleum, Anda 151400, China;2. China University of Geoscience, Beijing 100083, China

详细讨论了利用Biot-Gassmann方程计算储层条件下砂岩纵、横波速度的方法,并利用计算结果对纵、横波速度的变化规律进行了分析。该方法综合考虑了骨架成分、泥质含量、孔隙度、流体成分、饱和度以及温度和压力对油气层速度的影响。这种方法既可用来预测储层条件下油气层的速度,研究各种因素对速度影响的程度;又可用于模拟分析储层特性变化对地震响应的影响。特别是对油藏动态时移地震监测的理论研究与可行性分析具有重要的意义。

The method calculating velocities of P and S-waves of sandstone by Biot-Gassmann equation is discussed, and the velocity regularities of P and S-waves are analyzed on the estimation results. The method takes account of the influence of skeleton composition, shale content, porosity, fluid composition, saturation, temperature, and pressure on P and S-waves velocities of oil and gas reservoirs. The method can predict the velocities of oil and gas reservoirs under in-situ conditions, study the degree of various factors affecting velocities, and analyze as well as simulate the effects of reservoir characteristic variations on seismic responses. The method is particularly valuable to theoretical study and feasibility analysis of time-lapse seismic monitoring on reservoir performance.