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CALCULATIONS OF DATUM STATICS IN REFLECTION METHOD WITH CONSIDERATION TO THE POSITION OF THE CHARGE RELATIVE TO THE BASE OF LOWVELOCITY LAYER

A. P. Sysoev, A. A. Shamordin

Saint Petersburg Mining University, Saint Petersburg, Russia

While processing ground-based seismic operations by the reflection method using an explosive excitation source, the standard method of compensation technique for the inhomogeneity of the low velocity layer (LVL) is based on the use of blastholes parameters: shot depth, TSP and velocity of underlying stratum, determined by the apparent velocity of refracted wave. The necessary condition for the applicability of this method is the arrangement of the charge below the base of the LVL. Therefore, to substatiate this method, it is necessary to evaluate the position of the charge relative to the roof of the LWL for each source. If the necessary condition for calculating statics computations is not met, it is necessary to solve the problem of estimating the LVL’s thickness and velocity. The presented work contains the problem of analyzing the position of the charge relative to the LVL’s position and estimating the layer parameters which is solving on the basis of joint analysis of the parameters of wells and wave refracted on the LVL base. The solution of the problem is illustrated by the example of real data processing.

Keywords: lower velocity layer, datum statics, refracted wave, TSP, shothole depth.

DOI 10.20403/2078-0575-2022-2-57-61

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