弱弹性介质中炸药震源大基距面积组合激发效果分析

摘要

针对地震勘探中弱弹性介质(弹性较差的介质)地震波激发问题,如何更好地利用弱弹性介质的弹性性质是改善激发效果的关键.根据井中炸药震源激发的特点,通过大面积组合激发可以增加对弱弹性介质的作用面,即可以较好利用弱弹性介质的弹性特点,从而激发出较强的弹性波.在黄土塬和灰岩区分别进行了不同组合井距的面积组合激发试验,对试验资料的分析表明,随着组合基距的增大.不仅激发地震波的信噪比提高,而且地震波的能量也有所提高.这一结果表明,增大激发作用面可以有效地改善在弱弹性介质中的激发效果.%For the activation of seismic waves in weak e-lastic medium (medium with poor elasticity), how to make better use of its elastic properties is the key to improving shooting effects. According to the shooting characteristics of borehole dynamite source, shooting with large areal array increases the acting surface for the weak elastic medium, which means the elastic features of weak elastic medium can be better revealed and better elastic waves can be excited. Areal array shooting experiments with different group lengths are carried out in loess tableland and limestone regions, respectively. Analysis of the experimental data shows that besides the improvement of signal-to-noise ratio of seismic waves, the energy of seismic waves enhances with the increase of group length. The results show that increasing the acting surface can effectively improve the shooting effects in weak e-lastic medium.