【摘要】 在含孔、裂隙介质弹性波动统一理论的基础上,研究裂隙发育对低孔含气地层弹性波速度的影响。针对岩心测量的纵横波速度,探讨估算岩心裂隙密度的方法。结果表明:随着裂隙密度的增加,弹性波的速度降低明显;地震、测井和实验室岩心测量频率下的波速变化明显,显示出了较强的频散特性;在孔隙度为1.1%时,裂隙发育岩石在饱含气时的纵波速度与饱含水相比明显降低,裂隙密度为0.15和0.35时,500 kHz下的纵波速度分别下降了7.6%和27%;井孔模式波的衰减与速度相比对含气的敏感性更高,这为利用声波测井方法识别孔隙流体性质提供了思路。更多还原

【Abstract】 Based on the unified elastic wave theory which describes the effect of both pores and cracks,the influence of crack strength on the acoustic velocity of cracked low-porous gas reservoir was studied. According to the compressional and shear wave velocity obtained by measuring the core samples,the estimation method of formation crack density was investigated. The results of numerical calculation show that the elastic wave velocities decrease with the crack density increasing,and the velocity dispersions become obvious. When the porosity is 1.1%,the compressional velocity of gas-saturated rock is lower than that of water-saturated rock. When the crack density is 0.15 and 0.35,the compressional velocity for 500 kHz decreases by 7.6% and 27% respectively. The attenuation of borehole mode waves is more sensitive to gas saturation than the velocity,which provides a new way of identifying pore-fluid nature by acoustic logging technology.更多还原