Methodology of VSP data processing
Vertical seismic profiling is a powerful and widely implemented method of seismic exploration. It suggests a lot of opportunities for detailed reservoir study including velocities and anisotropy estimation, direct impulse shape registration, timedepth correlation, multi-wave analysis and imaging. These advantages of the VSP method are well known but often they become severely spoiled as a result of inappropriate processing techniques. In this paper we establish a number of general principles of VSP data processing and particularly for accurate wave field decomposition that ensures the high quality and reliability of acquired results of processing and interpretation. Examples of real VSP data processing are also presented to illustrate the application of the proposed techniques.
VSP data processing based on 1D-3D model of medium.
The conceptual VSP-oriented 1D-3D model is presented as convenient base of VSP processing and interpretation. The results of processing confirm the efficiency of technology in various applications.
High-Resolution Prediction of Acoustic Impedances Below BOTTOM-OF-HOLE*
TAL-VIRSKY, B.B. and TABAKOV, A.A. 1983, High-Resolution Prediction of Acoustic Impedances below Bottom-of-Hole, Geophysical Prospecting 31,225-236. Prediction of acoustic impedances below bottom-of-hole developed in the paper is based on VSP data processing. The pulse form and reflections are deduced from records on the vertical array by the method of subtraction. A deterministic prediction error and a waveshaping Wiener filter are used to transform the pulse train and reflections into a short symmetrical pulse. Additional broadening of the pulse spectrum is achieved by stacking of seismograms from shots with various dominant frequencies after zero-phase transformation of downgoing waves. The inversion of seismograms is made after ideal spiking by means of a subtraction procedure. Acoustic impedances deduced are closely related to lithology of rocks below bottom-of-hole.