基于冲击振动疲劳分析的自动垂钻与多维减振联合提速系统冲击频率优选

Shock frequency optimization of automatic vertical drilling and multi-dimensional vibration reduction combined speed-up system based on shock and vibration fatigue analysis

针对破岩钻进过程中自动垂钻与多维减振联合提速系统在上部液动冲击器的持续冲击及地层反力作用下易出现疲劳损伤的问题,为实现冲击频率优选,利用疲劳分析软件nCode Designlife,对冲击振动条件下自动垂钻与多维减振联合提速系统的疲劳损伤规律开展研究。结果表明:在冲击振动条件下,上扶正器的顶端截面由于直接承受来自冲击器的冲击载荷作用而具有最大的疲劳损伤;冲击频率低于100 Hz时,系统最大损伤值随冲击频率的增大先增大后减小,当冲击频率高于300 Hz时,频率的变化不会改变系统的疲劳损伤状态。因此,相比于常规低频冲击器,推荐选用300 Hz以上的高频冲击器,可以有效缓解井下振动,减少工具的疲劳损伤。研究结果对现场参数选型有一定指导意义。

In the process of rock-breaking drilling,automatic vertical drilling and multi-dimensional vibration reduction combined speed-up system is prone to fatigue damage due to the continuous impact of the upper hydraulic impactor and the action of formation reaction force.In order to optimize the shock frequency,the fatigue analysis software nCode Designlife was used to study the fatigue damage law of automatic vertical drilling and multi-dimensional vibration reduction combined speed-up system under impact and vibration conditions.The results show that under the condition of shock and vibration,the top section of the upper centralizer has the largest fatigue damage due to the impact load directly from the impactor.When the shock frequency is less than 100 Hz,the maximum damage value of the system increases with the increase of the shock frequency.When the shock frequency is higher than 300 Hz,the change of frequency will not change the fatigue damage state of the system.Therefore,compared with the conventional low-frequency impactor,it is recommended to select the high-frequency impactor above 300 Hz,which can effectively alleviate the downhole vibration and reduce the fatigue damage of the tool.The research results have certain guiding significance for the selection of field parameters.