摘要
通过对四川山区纵、横波联合勘探方法的研究,本文提出了一种用炸药震源激发横波的新方法——导向延迟爆炸法。该方法是在激发井旁打一排导向井,并在导向井内置一小药包(导向药包),用延迟爆炸技术使其先于激发井内的主药包爆炸,待造成岩土排出、形成空洞或爆破漏斗后,主药包才开始爆炸。这样,可增大主药包爆轰时所产生的定向剪切力,使之产生较强的水平偏振。用此法所获得的横波记录能量很强,信噪比高。文中还研究了炸药震源(导向延迟爆炸)与水平检波器的方向性,证实了导向延迟爆炸所激发的横波是SH波(水平偏振横波)。另外,根据震源激发机制和纵波与SH波的噪声特点及其时一空域分布关系,提出了山区纵、横波联合勘探的野外观测方法。
Directional delayed shot, a new method for generating S-wave with the use of dynamite, is adopted on the basis of research on combin- ed P-wave and S-wave survey in mountainous region in Sichuan Province. This method needs a row of 'direction-guidance'wells drill- ed near the seismic source point, a small charge being placed in each well. With the use of delayed blast technique, the small charges explode to create cavities or 'explosion funnel' before the exploding of the seismic source charge, so that the seismic source charge ex- plodes to cause directional shear stress which results in strong hori- zontal vibration. The shear wave record obtained in this method has high energy and high S/N ratio. The directionalities of the directional delayed blast and horizon- tal detector are analysed.The analysis shows that the directional de- layed blast generates SH wave (shear wave generated by horizontal vibration). Field observation method for combined P-wave and S- wave survey in mountainous region was developed on the basis of analysing shot mechanism, noise properties and the distributions of useful waves and noises in time-space domain.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
1991年第6期733-743,799,共12页
Oil Geophysical Prospecting
关键词
横波震源
导向延迟爆炸
导向井
联合勘探
shear wave source
directional delayed blast
direction guidance well
combined survey
