【摘要】 地震波激发方式是影响地震数据采集质量的重要因素之一。利用波动方程有限差分方法对细长药柱震源、时延爆炸震源、相控爆炸震源、水平组合震源等常用的4种地震波激发方式进行了正演模拟,从理论上研究了相同药量情况下不同激发方式的波场特征差异,以及不同激发条件下的能量照明关系。模拟结果的对比分析表明,组合震源和相控震源随着炮数的增加其激发地震子波的能量越来越集中,向下传播的能量越来越多,有利于深层勘探;时延震源也具有一定的定向性;而柱状震源激发时能量向两边扩散,不利于深层地震勘探。对于水平地层,时延震源激发要比组合震源激发方式效果差,但可以通过增加延迟震源的基间距来提高其定向性,进而增加地震波向下传播的能量,实际应用中应根据工区地质情况和地震采集成本来选取。而对于倾斜地层,组合激发的效果比延迟激发效果要好很多,相控激发的效果最好。所以,对于勘探区是倾斜地层的情况,特别是大倾角的地层,建议使用相控震源激发。更多还原

【Abstract】 The pattern of seismic source excitation is one of the main factors to influence the quality of seismic data acquisition.Based on the method of finite difference numerical simulation,we carried our forward modeling on four typical excitation means,including elongated dynamite source,time-lapse dynamite source,facies-controlling dynamite source and horizontal array source.Theoretically,the wavefield characteristics and energy illumination figures of different excitation patterns under the circumstance of same dynamite charge are studied and analyzed.The comparison and analysis on simulation results show that along with the shots increasing,the energy of seismic wavelet shooting by array source and facies-controlling source is more accumulated,which is beneficial for the exploration on deep layers.Moreover,time-lapse source has orientation capability.However,the energy diffuses to the two sides as columnar source shooting,which is not beneficial for the exploration of deep layers.For horizontal layers,time-lapse source shooting has worse effect than array source,but can increase the base interval of time-lapse sources to improve the orientation capability and strengthen the down-going energy propagation.In actual application,we should select the shooting means in terms of area geological conditions and seismic acquisition cost.But for dip layer,array shooting is better than lapse shooting,and the facies-controlling shooting is best.As a conclusion,facies-controlling source shooting is suggested for the dip formation,especially for the high-dip formations.更多还原