Study on shooting mechanism of seismic waves in limestone-exposed area
Yang Qin-yong, Chang Jian, Xu Guo-qing
Nanjing Research Institute of Petroleum Geophysical Exploration,SINOPEC Research Institute of Petroleum Exploration and Development,Najing City,Jiangsu Province,210014,China
Abstract:The selection of seismic shooting factors is an important link affecting seismic data quality. The study of seismic shooting mechanism showed that the weak seismic energy by dynamite shooting in limestone-exposed area has become bottleneck restraining seismic exploration in that area. For that reason,starting from the studying seismic shooting mechanism in limestone area,the paper analyzed the main factors of seismic waves shot by explosion and developed numeric simulation,in-site experiment and physical simulation correspondingly,which gained following conclusions:it should increase explosion impulse and acting time on limestone to improve the shooting condition in rigid bed such as limestone; selecting reasonable geometric coupling coefficient,increasing charge size with low explosive speed,using filling medium in shot-well and ensuring good closed borehole to implement explosion.