气体钻井稳定器设计及结构参数对工具性能的影响

Gas drilling stabilizer design and influence of structural parameters on its performance

针对气体钻水平井中岩屑在下井壁滞留和聚集的问题,设计了一种气体钻井专用稳定器,所设计的新型结构可避免稳定器处发生沉屑卡钻或减少其发生几率。基于气-固两相流理论和数值模拟技术,提出了稳定器工作性能优劣的评价指标,并研究了稳定器结构参数(流道入出口径、槽深、窄流道位置、螺旋度、螺旋棱轴向长度、螺旋棱形状)对稳定器工作性能的影响。研究表明:在气体循环介质条件下,结构参数对稳定器的工作性能影响很大,燕尾槽形的流道入出口和零端面厚度的螺旋棱导流坡面复合结构可以有效解决稳定器入、出口端的岩屑粒子反射和沉降问题。直径为215.9mm稳定器可用于气体钻井,特别是气体钻水平井中,提出的工作性能评价方法和研究结论可指导其他规格气体钻井稳定器的设计。

In terms of the intention and accumulation of cuttings in low side wellbores in horizontal-well gas drilling,a drill stabilizer was designed particularly for gas drilling and this stabilizer with novel structures can prevent drill pipe from sticking caused by cuttings settlement or reduce the occurrence probability of drill-pipe sticking in gas drilling.Based on the gas-liquid two-phase flow theory and numerical simulation,we proposed evaluation indices for the stabilizer performance and studied effects of stabilizer structural parameters on the stabilizer performance,such as inlet and outlet apertures of flow channels,groove depth,narrow flow channel locations,helicity,and spiral edged shape.The results showed that structural parameters may significantly affect the stabilizer performance on conditions of gas circulation media,composite structures of the inlet and outlet of dovetail-shaped flow channels and the helical edged diversion slope with zero end-edge width can effectively solve the rebound and settlement of debris particles in the inlet and outlet of the stabilizer.A stabilizer with the diameter of 215.9mm can be used in gas drilling,particularly in horizontal-well gas drilling.Performance evaluation methods proposed in the present paper and its conclusions are of guide significance in designing specifications of the other gas-drill stabilizers.