【摘要】 震源是油气资源勘探和微地震监测中很重要的部分。为恰当地选择地震波勘探震源、节约野外勘探成本,文中基于加载压力源、剪切源和集中力源的理论公式,通过交错网格有限差分法数值模拟获得震源在各向同性介质中的地震波场图,详细讨论震源激发波的分布特征。通过波的偏振理论,从物理上细致地分析震源产生地震波的机理,与解析解一并验证数值模拟结果。所得结果说明:震源力是数值模拟地震波场的可控性因素;震源在三维裂缝介质中可观测到横波分裂现象;物理分析是很好地解释地震波场分布图的一种验证方法。更多还原

【Abstract】 Seismic source is an important part in the exploration of oil and gas resources and microseismic monitoring.Based on the equations of loading source on pressure source,shear source and centralized source,the authors obtained seismic snapshots in isotropic medium through triggered-grid finite difference scheme simulating and discussed in detail pattern characteristics of wave excited sources so as to choose the most suitable source to save the exploration cost. The authors analyzed in detail the mechanism of excited seismic sources from wave polarization theory of physics and,together with the analytical solution,verified the results of numerical simulation.It is concluded that the force is the controllable factor of obtaining seismic source field,the source used in 3-D fracture media can observe shear splitting,and physical analysis is a kind of verification method for explaining the pattern of seismic wave.更多还原