偏轴钻具组合防斜打快的强度分析

针对偏轴防斜打快技术中所用的钻具组合的受力状态复杂,对整个钻柱系统的安全性有较大影响的问题,考虑安全、有效的钻井施工特别需要对偏轴接头及接头附近的钻铤强度进行分析,找出钻具组合的危险点,以便于校核钻具组合的强度和改进偏轴钻具组合的结构设计的实际.以下部钻柱为研究对象,将钻头以上部分分成多个梁单元,进行结构离散,建立力学模型,采用有限元分析方法,进行偏轴接头强度分析.研究表明,偏轴钻具防斜钻具组合的最大复合应力发生在偏轴接头与下部钻铤的结合部位,主要由弯曲载荷和轴向力产生.在应力最危险部位,应特别注意钻具的强度安全问题.

STRENGTH ANALYSIS OF BHA WITH ECCENTRIC SUBASSEMBLY IN DEFLECTION CONTROLLING AND DRILLING FLEETLY

In terms of certain conditions, to use the assembly of bevel strings is one of the best effective fleet inclined-proof drilling techniques. The force-received estate of assembly of bevel strings which is applied in the technique of bevel strings fleet inclined-proof is very complex and greatly affects the security of whole drill string system. In order to realize a safe, effective drilling operation, to analyze the strength of bevel joint and its neighboring drill collars is very necessary. At the same time, it's very important to find out the danger point of assembly, and it's very expediently to proofread the strength of drilling strings and improve its structural design. Some research indicates that the most compound stress of bevel inclined -proof strings is commonly situated in the bonding site of bevel joint and underneath drill collar which is derived from the bend load and axial force. In the most dangerous place, the security of drilling tool's strength should be concerned especially.