675型泥浆脉冲器短节应力分析及结构设计优化

Stress analysis and structural design optimization of Type 675 mud pulser sub

摘要:

为给钻柱上功能短节的结构设计及优化提供指导，以承受压弯扭组合载荷的极限工况为例，对675型仪器串的泥浆脉冲器短节模型进行简化处理，建立了有限元分析模型。针对675型仪器串上泥浆脉冲器短节的结构特点，对泥浆脉冲器短节的不同区域采取不同的网格划分方法。在模型两侧添加工装以进行复合加载，对于压弯扭组合载荷中的弯曲载荷，通过计算极限狗腿度下产生的最大挠度进行等效加载。分析结果表明，在压弯扭组合载荷共同作用的极限工况下，应力集中现象主要出现在钻铤及电子骨架上，开孔及开槽处为薄弱位置，基于分析结果提出了675型仪器串泥浆脉冲器短节的结构改进建议。本文提出的分析方法和设计经验可为此类功能短节设计及优化提供参考。

Abstract:

To provide guidance for structural design and optimization of the functional sub in the drill string， the model of the mud pulser sub in Type 675 instrument string is simplified and the finite element analysis model is created in the case of the extreme working condition under the combined load of compression， bend and torsion. Considering the structural characteristics of the mud pulser sub in Type 675 instrument string， different mesh division methods are adopted for different sections of the mud pulser sub. Fixtures are added on both sides of the model for composite loading， while equivalent loading is applied for the bend load in the combination of compression， bend and torsion load by calculating the maximum deflection under the limit dogleg. The simulation results show that under the combined load of compression， bend and torsion， the stress concentration phenomenon mainly occurs in the drill collar and the electronic framework， and weak positions such as openings， grooves. Based on the analysis results， suggestion is put forward on the structural improvement of the mud pulser sub in 675 instrument string. The analysis method and design experience presented in this paper can provide reference for the design and optimization of the functional sub of the same kind.