A logging-while-drilling acoustic logging method and device based on dual-source flyback technology

Abstract

The invention discloses a method and a device for acoustic logging while drilling based on dual-source flyback technology. The present invention adopts two emission, far and near. When logging, the far emission Tf is first excited, the emission amplitude is A1, the near emission Tn is excited after a delay of a period of time τ, the emission polarity is opposite to Tf, and the amplitude is A2 ; At the same time when the sound source is excited, the signals on N receivers are collected and recorded; the drill collar waves excited by the far and near emission at the position of the receiver arrive at the same time, have opposite polarities and the same amplitude, and are canceled after superposition. , so as to suppress the drill collar wave. In the subsequent data processing, the sonic interference method is used to further suppress the influence of the residual drill collar wave, and the velocity of the formation wave is extracted. Thus, an acoustic logging-while-drilling technology that does not require a sound insulation device is formed. The invention solves the interference problem of the drill collar wave during the monopole longitudinal wave logging while drilling, avoids the damage of the drill collar strength caused by the groove design, and reduces the mechanical processing difficulty and the manufacturing cost of the instrument.

Description

technical field [0001] The invention belongs to the field of geophysical logging, and relates to an acoustic logging method and device while drilling, in particular to an acoustic logging method and device based on dual-source flyback technology. Background technique [0002] Acoustic logging is an important geophysical logging method. Its main purpose is to measure the velocity of compressional and shear waves in the formation, and then evaluate the reservoir parameters such as the porosity of the formation. The Logging While Drilling (LWD) technology has developed rapidly in the past ten years. Because it can complete the logging operation while drilling, it greatly saves the time occupied by the drilling rig, especially in the current increasing offshore oil and gas exploration and development operations. It has a good application prospect. However, as one of the key technologies of logging while drilling, the sonic logging while drilling technology is relatively lagging...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a method and device for acoustic logging while drilling based on dual-source flyback technology, so as to solve the interference problem of drill collar waves during single-pole longitudinal wave logging while drilling. The link suppresses the drill collar wave to improve the signal-to-noise ratio of the formation wave, and adopts the data processing method of acoustic wave interferometry in subsequent data processing, thus forming an acoustic logging while drilling technology that does not require sound insulation devices

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