双相TI介质中弹性波交错网格高阶有限差分法数值模拟

应用双相介质波动方程,推导了双相横向各向同性介质(TI)中波动方程的有限差分格式,对双相TI介质中弹性波有限差分数值进行了模拟.结果表明,弹性波在双相TI介质中传播时,除了存在常规的快纵波(qP1)和横波以外,还存在慢纵波( qP2).并且慢纵波的速度明显小于快纵波,而且受耗散系数的影响衰减地很快,所以在实际中很难观测到慢纵波.快纵波在固相和流相中相位相同,而慢纵波在固相和流相中的相位相反.慢纵波在流相中振幅大,而在固相中的振幅较小.

ELASTIC WAVE NUMERICAL SIMULATION IN TWO-PHASE TRANSVERSELY ISOTROPIC MEDIUM BY HIGH-ORDER STAGGERED-GRID FINITE DIFFERENCE METHOD

Finite differential format of wave equation in two-phase transverse isotropic media(TI) is obtained by solving two-phase media wave equation,and the numerical simulation of elastic wave finite difference is carried out in two-phase TI media.The results show that in the two-phase elastic wave propagation in TI media,in addition to existing conventional fast P wave(qP1) and S wave,there is slow P wave(qP2),slow P wave was significantly less than the speed of fast P wave,and the dissipation coefficient attenuate very quickly,so in practice it is difficult to observe slow P wave.The phase of the fast P wave is same in both solid phase and liquid phase,and that of the slow P wave is reverse.the amplitude of the slow P wave in liquid phase is bigger than that in solid phase.