Method of extracting of shear wave velocity of dual-spaced full-wave train logging based on slowness-time

Abstract

The invention discloses a method of extracting the shear wave velocity of dual-spaced full-wave train logging based on slowness- time, comprising S1, reading the first wave of the log data, and obtaining longitudinal wave velocity Vp based on the time difference between the dual-spaced two probes; S2, calculating the degree of correlation between different time waveforms; S3, determining the corresponding longitudinal wave energy mass development position based on the first wave extracted in step S1; S4, enclosing the transverse wave mass based on the longitudinal wave velocity and the development range of the transverse waves on the time shaft; S5, separately extracting and integrating the longitudinal and transverse energy mass on the slowness- time correction spectrum to get correlation coefficient curve of the separated longitudinal and transverse waves in the slowness domain; and S6, extracting the transverse wave peak to get the slowness of the transverse wave, and converting the slowness into velocity to get the transverse wave velocity of dual-spaced full-wave train logging. The invention had the advantages of reduced human intervention and accurate and stable transverse wave velocity results.

Description

technical field [0001] The invention relates to a method for extracting shear wave velocity of rock mass, in particular to a method for extracting shear wave velocity of double source spacing full wave train logging based on slowness-time. Background technique [0002] The shear wave velocity of the rock mass is an important parameter to obtain the Poisson's ratio, bulk modulus and shear modulus of the rock mass, and it is also an important characterization of the porosity and cracks of the rock mass. The rock mass sample obtained by borehole sampling is different from the undisturbed formation, and the velocity information of the rock mass fracture zone cannot be obtained directly. In engineering geological survey, full wave train logging with dual source spacing is often used to obtain the compressional wave and shear wave velocity information of in-situ rock mass. [0003] The dual-source full-wave train logging technology commonly used in engineering geological surveys,...

AI Technical Summary

Problems solved by technology

This method essentially extracts the first arrival of the shear wave, but due to the influence of multiple factors such as signal interference, longitudinal wave and follow-up wave, the first arrival of the shear wave is not obvious, so this method is greatly affected by human factors

[0012] It is difficult to extract the shear wave velocity in the dual-source full-wave train acoustic logging data. The current dual-source full-wave train logging mostly only provides the compressional wave velocity of the formation, and there are few successful cases of extracting the shear wave velocity.

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