High-Precision Iterative VSP Wavefield Separation

Conventional vertical seismic profiling (VSP) wavefield separation method (CSM) focuses on the wavefield separation result, not the residual. Iterative zero-offset VSP (ZVSP) wavefield separation method (IZSM) can obtain high-precision results. However, IZSM can only be used for ZVSP data, which limits its application. The scalar wavefield separation algorithm used in IZSM is the SVD filtering, which limits its precision. The objective function threshold of IZSM is varied with the input ZVSP data, which limits its result precision and efficiency. To improve the wavefield separation precision and efficiency, we propose a high-precision iterative VSP wavefield separation method (HISM). HISM is suitable for both ZVSP and offset VSP (OVSP) data and is also applicable for any possible scalar wavefield separation algorithm. The objective function threshold of HISM can be a fixed number. Therefore, HISM can obtain high-precision and efficiency results. Actual ZVSP and OVSP data application demonstrates the performance of HISM.