Three-component sound wave far-detection logging device and measuring method thereof

Abstract

The invention provides a three-component sound wave far-detection logging device and a measuring method thereof. A downhole sound wave far-detection instrument comprises a helical wound high temperature resistant optical fiber and a spiral tube form wound the outside of a cylinder structure; an optical fiber gyroscope and a downhole array type sound source generator are vertically and successivelyinstalled on the lower part of the cylinder structure; a ground wellhead logging truck controls lifting of the downhole sound wave far-detection instrument in a well, a power source is provided for the downhole sound wave far-detection instrument, and the downhole array type acoustic sound source generator is driven to continuously and repeatedly emit sound signals during operation; and a groundDAS modulating and demodulating instrument is connected with the helical wound high temperature resistant optical fiber, a laser pulse is emitted into helical wound high temperature resistant opticalfiber, and backscattering Rayleigh waves in the downhole helical wound high temperature resistant optical fiber are collected. The three-component sound wave far-detection logging device can work under the high temperature for a long time, and the high speed upward data transmission function is realized.

Description

technical field [0001] The invention relates to the technical field of geophysical exploration, in particular to a three-component acoustic wave remote detection logging device in a well based on a distributed optical fiber sensing technology and a measurement method thereof. Background technique [0002] Sonic logging refers to a logging method that uses different acoustic properties such as velocity, amplitude and frequency changes when sound waves propagate in different rocks to study the geological profile of drilling and judge the quality of cementing. Sonic logging is a logging method that determines the properties of rock formations by studying the speed of sound wave propagation in the rock formations in the borehole. Commonly used sonic velocity logging tools include a sonic generator (T) and two receivers (R., R.). The recorded parameter is the time difference (Δt) for the sound waves to reach the two receivers, ie the time it takes for the sound waves to travel i...

AI Technical Summary

Problems solved by technology

[0009] The current downhole acoustic remote detection instruments use unipolar or dipole or multipolar piezoelectric acoustic transducers to receive the reflected wave signal reflected back into the wellbore from the wave impedance interface far away from the wellbore. Dipole or multipole piezoelectric acoustic transducers and their supporting amplifiers, analog-to-digital conversion and data storage devices, and downhole data transmission modules cannot work for a long time in high temperature environments (deep wells)

In addition, since the downhole acoustic remote detection instruments are currently electronic instruments, the downhole data transmission module cannot solve the bottleneck problem of real-time transmission of downhole big data to the control computer in the wellhead logging vehicle at high speed.

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