Through drill bit dipole acoustic logging emitter and logging device

Abstract

The invention relates to an emitter of a through drill bit dipole acoustic logging device and the logging device. The emitter comprises a base plate and 2n piezoelectric ceramic plates. Each piezoelectric ceramic plate is composed of 2n piezoelectric ceramic units. The two ends of the base plate are provided with through holes. The base plate is fixed to the through drill bit dipole acoustic logging device through the through holes by means of fixing pieces. During work, the piezoelectric ceramic plates on one side of the base plate extend, the piezoelectric ceramic plates on the other side of the base plate shorten, and the base plate is pushed to form bending vibration to radiate thrust towards a medium so as to generate acoustic waves. The sectional type dipole emitter has the characteristic of low-frequency and high-power emission and is suitable for a transducer in through drill bit small-diameter acoustic logging and more suitable for transverse wave measurement of soft stratums and even super-soft stratums.

Description

technical field [0001] The present invention relates to the technical field of mineral resource exploration and development, especially in the fields of mine geophysics (logging) technology, drilling measurement technology and measurement-while-drilling technology, and especially relates to a through-drill dipole acoustic logging transmitter and Logging device. Background technique [0002] Formation evaluation before and after hydraulic fracturing of large horizontal well sections (such as more than 1000 meters) is a hot spot, difficulty and key technology of shale gas development in my country. The through-bit orthogonal dipole acoustic logging technology is the preferred measurement method to solve this problem at present. [0003] Through-bit logging is a new technology developed in recent years. Through-bit logging refers to a method in which the logging instrument passes through the drill bit and enters the well section for logging data acquisition. The through-bit ...

AI Technical Summary

Problems solved by technology

Due to the small outer diameter of the through-drill instrument (54mm), the geometric dimensions of the crystal and the substrate of the laminated bending oscillator are correspondingly reduced, which makes the orthogonal dipole transducer assembled, compared with the conventional orthogonal dipole Compared with the curved array, the sub-acoustic instrument has a narrower radiation surface, which causes the excitation energy of the transducer to weaken and the signal-to-noise ratio to decrease.

Images