随钻地震波场高阶交错网格有限差分数值模拟

 随钻VSP是利用钻头振动噪声作为震源,在地面布设检波器进行信号接收的一种新的物探技术。基于随钻地震波场的空间传播特征,从一阶速度-应力波动方程出发,利用高阶交错网格有限差分,模拟出不同炮点深度和不同偏移距情形的随钻地震波场,研究随钻地震波场的空间传播规律和特征。结果表明,数值模拟可以有效的解决现场试验周期长,费用高,地下结构未知因素多等问题,为随钻地震技术研究提供了一种高效的手段。

High-order Staggered Finite-difference Numerical Simulation of While-drilling Seismic Wave Field

The while-drilling Vertical Seismic Profile (VSP) is a new kind of geophysical prospecting techniques which uses the noise of drill vibration as its seismic source and receives signal by the wave detector deployed on the earth. The vibration of rock-drill is random and continuous, and the wave signal is weak. However, the noise in the well field is strong, and the waves of different times and seismic phases superpose and interfere with each other. As a result, these factors make the SNR of while-drilling seismic data too low and result in the complexity of wave field, in the meantime, make the data processing much more difficult. By using high-order staggered grid FD, it could simulate while-drilling seismic wave field with the different shotpoint depth and different offset distance from the first-order velocity-stress wave equations. Finally, the study on the spatial propagation regulation and characteristics of while-drilling seismic field is able to guide the processing and interpretation of practical while-drilling seismic data.