【摘要】 为了研究构造煤的地震特征及可识别性,根据常温常压条件下超声测量所揭示的原生结构煤与构造煤的弹性特征,建立了3种典型的煤层夹构造煤地震地质模型;利用反射率法计算了这3种模型的PP波与PS波地震响应;在不同频率下对比分析了构造煤所处位置及厚度大小对煤层反射的影响及其AVO特征。结果发现:构造煤夹层的存在使煤层反射系数增大;频率越低、构造煤厚度越大,增加的倍数越高;相同条件下PP波反射系数的增幅高于PS波;在低频情况下,构造煤在煤层中的空间位置变化在煤层反射的相位上存在异常。从而从理论上证明利用现有的纵波地震反演技术,理论上可以预测构造煤的存在;PS波信息的加入有助于提高单纯PP波预测的精度,尤其对构造煤空间位置的确定,PS波相位具有优于PP波的敏感性。更多还原

【Abstract】 To analyze the seismic characters and recognition of deformed coal,according to the ultrasonic elastic characteristics of deformed coals under room temperature and normal press,three typical seismic geological models were initially designed. Seismic responses of these three models were simulated with reflectivity method,and their AVO characteristics were analyzed and focused on the influence of the deformed coal’s spatial location and thickness on seismic response in different frequencies. The comparisons show that the existence of deformed coal changes the reflection coefficients of coals models,and the amplitudes of reflection coefficients increase. With the lower frequency of the incident waves and the thicker of the deformed coal,the multiple increases significantly. Amplitude’s growth rates of PP-wave reflection coefficients are higher than those of PS-wave under the same conditions. Applied jointly with the thickness prediction technology of coal seam,the phase of reflection coefficient can be used to distinguish the relative spatial locations between deformed and un-deformed coals in terms of low frequency. Only using P-wave seismic inversion technique,the deformed coals can be predicted in theory. However,the precision will be improved if PS-wave is considered at the same time,especially for the spatial location prediction of deformed coal.更多还原