Abstract:Generally, same explosive have different impacts on porous media with different porosity ratio, and different explosives also have different impacts on the same media. In this paper, the influence of geometric and impedance coupling on the excitation in porous media is respectively analyzed and the relationship of explosive energy efficiency with time are shown. The following observations were obtained through theoretical analysis and model tests: ①Increasing non-coupling coefficient can result in a decrease of the particle velocity and the pressure in the early explosion, and the particle velocity and pressure may increase with time. So certain reasonable uncoupled charge may be more powerful for elastic energy generation. ②When seismic waves were excited in carbonate rocks with high velocity and high density, increased porosity ratio can cause increased particle velocity and decreased pressure on hole walls. In the early explosion, energy and energy efficiency increase with porosity ratio, while those of low-porosity ratio media increase more rapidly with time. So it is necessary to have consideration on both springing and wavelet energy of the excitation media. ③When seismic waves were excited in loess media with low velocity and low density, the particle velocity and pressure on hole wall increase with porosity ratio, and the porosity ratio has much more influence on energy and energy efficiency with time. The above observations can be referenced for explosives selection in different lithology.
Zhong Mingshou, Long Yuan, Li Xinghua et al.Influence of borehole non-coupling coefficients on detonation effectiveness of seismic source in carbonate rock.OGP,2011,46(2):165-169.
[5]
刘保林,周芝旭,殷厚成等.山前带地震勘探实践.北京:石油工业出版社,2005.
[6]
林大超, 白春华.爆炸地震效应.北京:地质出版社,2007.
[7]
高金石, 张奇.爆破理论与爆破优化.陕西西安:西安地图出版社,1993.
[8]
刘洪文.济阳坳陷岩石密度与纵波速度的关系.油气地质与采收率,2008,15(6):26-28.
Liu Hongwen.The relation between density and P-wave velocity of rocks in Jiyang depression.Petroleum Geology and Recovery Efficiency,2008,15(6):26-28.
Cheng Hongtao,Huang Yongqin,Hu Rendong.The seismic exciting technique for the soil area areas in Erdos Basin.Chinese Journal of Engineering Geophy-sics, 2005,2(6): 460-465.