Fine shear-wave (S-wave) impedance access technology based on logging and prestack channel set seismic data

Abstract

The invention relates to a fine S-wave impedance access technology based on a logging and prestack channel set seismic data. The technology is characterized by calculating an elastic modulus of a dry rock matrix and a modulus of saturated fluid rock by a Xu-White equation; taking a conventional sound wave and a density logging as a datum curve based on the estimation of initial S-Wave speed, and correcting and inputting elastic parameters to obtain the initially corrected S-wave impedance information; and establishing an iterative inversion model via an error obtained by comparing the change rule changing with offset distance of amplitude of the prestack channel set and an actual outdoor seismic channel set synthesized by a P-wave and a S-wave and density information with a wave group by a rotation orthogonal direction-based method to finally obtain a S-wave impedance curve. The technology has strong adaptability, convenient operation, simple and easy calculation, strong anti-noise capability, stable S-wave parameters and the like, and position change of a plurality of main in-phase shafts between a synthetic channel set and the actual seismic channel set obtained by initial inversion parameters is consistent with the amplitude change.

Description

technical field [0001] The invention belongs to the field of seismic data interpretation, and is a method for obtaining fine shear wave information by comprehensively utilizing well logging and pre-stack seismic data. Background technique [0002] As the difficulty of oil exploration increases, geologists hope that seismic data can provide more information reflecting lithology and reservoir properties, and only the combination of compressional wave and shear wave impedance can more accurately judge reservoir lithology and identify Reservoir fluid characteristics. At present, most of the shear wave information acquisition methods are as follows: First, the shear wave logging curve is obtained by dipole shear wave logging and other technologies. seldom used. The second is through the fluid substitution theory, it is believed that the underground reservoir is composed of two parts: solid and fluid contained in the pores, calculated through the established theoretical model or...

AI Technical Summary

Problems solved by technology

The compressional wave impedance is provided by conventional logging curves, but the shear wave impedance data is very scarce. In order to solve the problems of harsh application conditions, difficult parameter selection, and large errors in the existing shear wave impedance estimation methods, the present invention provides comprehensive utilization of logging curves and stacked Techniques for Obtaining Shear-wave Impedance from Pre-Gather Data

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