| Sonic drilling is a technology that the drilling system driven by a hydraulicmotor efficiently, which make the formation liquefied partially so as to obtaincontinuous undisturbed sediment samples. It can be widely used in environmentaldrilling, mineral prospecting, exploration and other engineering fields. Drilling toolsin sonic vibration (including drill pipe, sampling tube and bit) is the transmission pathof power head’s vibration energy, which is also the contact boundary with the stratum.Conducting the research of vibration and fluctuation characteristics has a importantrole of improving energy transmission efficiency and the sampling effect of acousticvibration, which also has great significance for the promotion of this technology.This study introduced the research status of acoustic vibration drilling technology.Based on review of oil drilling string longitudinal vibration, I simplified the structureof drill, derived the acoustic longitudinal vibration model equations used ofone-dimensional wave equation, determined the corresponding initial and boundaryconditions and calculated the basic parameters of acoustic frequency drill simulatedlongitudinal vibration according to the theory of dynamical similarity.A hardware and software measurement system of acoustic frequency vibrationsimulation experiment platform was built. Two kinds of simulated drill-aluminumalloy drill and alloy steel drill were processed, which had a length of1.8m anddiameter of8mm. Vibration test for the two points at the top and bottom of the drillwas carried out in the simulation stage on different constraints and excitationconditions. And I analyzed the data in time domain and frequency domain. The resultsshowed that: there are damping consumption and resonance phenomenon ofvibrational energy in the drill string simulation, which were closely related to thematerials of the simulation drills, incentive method and constraint state. These resultsprovided a basis for quantitative analysis of acoustic frequency vibration energy.Simulation study on vibration characteristics of acoustic vibration drill wascarried out by multi-physics coupling analysis software COMSOL Multiphysics. Theexperimental results and results of simulation study is basically consistent.This article also fixed vibration models and constraint conditions by comparisonresults and conducted simulation analysis of structural parameters of actual drilling,which provided theoretical basis for optimizing the structure of acoustic frequencyvibration drilling and further exploration of drilling and sampling techniques. At the same time, the research of this paper could provided some references for vibration ofcoiled tubing underground and longitudinal vibration analysis of drilling tools inultra-deep hole. |
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