地层条件下岩石动静力学参数的实验研究

在实际地层三轴应力和温度条件下 ,测量了 CX地区地表至 50 0 0 m深度砂、泥岩样品的静力学参数。对其中大部分样品进行了岩石力学和声波速度 (v P,v S)的同步测试 ,由此获得了在相同应力和温度条件下岩石的动、静力学参数。根据实验结果 ,讨论了在实际埋深条件下CX地区砂、泥岩的静力学参数、波速及动力学参数的变化特征 ,以及岩石动、静力学参数间的关系。

Experimental study of dynamic and static mechanics parameters of rocks under formation conditions

Static mechanics parameters of the sandstone and mudstone samples from the surface to 5000 m depth in CX region are measured under formation triaxial stresses and temperature. Static mechanics parameters and ultrasonic velocities ( v P, v S) are also measured simultaneously for the most of these rock samples under formation conditions. The dynamic and static mechanics parameters of the rock samples in the same stress and temperature are obtained from the measurements. Based on the tested results, the authors discuss the characteristics of the static and dynamic mechanics parameters and wave velocities of the rocks in the real formation conditions. The static mechanics parameters of the sandstone increase with formation depth increasing . The variation of the parameters of the mudstone is not obvious. In the formation temperature and pressure conditions, the compressional and shear wave velocities and dynamic elastic modulus variation curves with differential stress are secondary curves. The stress in which the shear wave velocity attains to the peak value is a good criterion for the stress value of stress induced small cracks. The variation of the dynamic mechanics parameters with formation depth are similar to the static parameters. The relationship between the dynamic and static mechanics parameters of the rocks in CX region is also studied. There is a good linear relationship between the dynamic and static elastic modulus for the sandstone and mudstone in CX region. There is also a linear relationship between the dynamic and static Poisson's ratios.