Research On Vibration Test Method Of Downhole Drill String

With the development of drilling and logging technology, drill string vibration often bring bit larger damage, can also causes problems such as drill string fatigue failure and the wear of the drill string, therefore, the harm of the drill string vibration is considerable. As the internal characteristics of drill string and the situation of the operation can be reflected through the vibration signal, therefore, in order to recognize the working condition of the drill string and mechanical failure which may occurs, the drill string vibration testing method is studied in this paper.This paper researches the research status of the drill string vibration test at home and abroad at the first, and then studies the relevant theories of the drill string vibration.The overall design of the drill string vibration test system is completed, analysis of the each component of the system and functional features briefly, this paper expounds the system function requirement, the technical indexes of the system is introduced, analysis of the application environment of the system.Drill string vibration test system mainly consists of two parts of hardware system and software system. Drill string vibration test hardware system is designed, application of piezoelectric acceleration sensor in the field of the drill string vibration test is analyzed, designing the hardware system’s overall framework, analyzing the effect of each component, designing a small charge amplifier and analyzing the functions and features of PCI-8735data acquisition card briefly; Drill string vibration test software system is designed, using LabVIEW graphical programming language for software programming, puting forward the demand analysis and the overall framework of the software system, the drill string vibration test system main interface and each function module design are completed.The drill string vibration test system is demarcated and validated. The sensitivity of drill string vibration test system is determined. The three-dimensional rectangular coordinate system is established for the simulation of the drill string vibration test, the simulation test of the drill string longitudinal vibration, lateral vibration, random vibration and jump vibration are completed separately, the drill string vibration signal in the time domain waveform and spectrum characteristics are analyzed.