多震源地震正演数值模拟技术

A numerical modeling of simultaneous sources

常规地震采集技术因受相邻时间激发炮之间时间间隔的制约而存在采集周期过长,采集成本过高的问题,而多震源同步激发地震采集技术可以克服这方面的缺陷,但存在着波场过于复杂的问题,地震正演模拟技术可以帮助我们提高对这种复杂波场的认识水平,为此采用2D弹性波方程交错网格高阶有限差分格式,开发了多震源同步激发波场正演数值模拟技术,能够模拟任意多个同步激发震源的弹性波波场,震源函数可以是雷克子波,也可以是可控震源扫描信号,且同步激发震源之间可以有随机时差.模型试算结果分析表明,该技术既是一项高精度的多震源正演模拟技术,也是一项高效率的地震正演数值模拟技术.

Conventional data acquisition practice is confined to the existence of time intervals between the firing of successive sources in the field, in order to avoid interference sources are fired with large time intervals, which leads to time-consuming and expensive survey. Simultaneous multisource acquisition can overcome the defects, but the wave field of acquiring data is very complex. Seismic forward modeling techniques can help us improve the understanding level of the complex wave field, therefore , based on 2D elastic wave equation, a staggered grids high order finite difference format was used to develop simultaneous multisource modeling technology. This technology can simulate any number of simultaneous sources of elastic wave field, the source function is wavelet, also can be a vibroseis sweep signal, and there being random time difference between the simultaneous source. The modeling results show that the technology is both a high precision of the forward modeling technology with multisouree, and is also a high efficiency seismic forward modeling technology.