水平井V形岩屑床清除工具研制与应用

Development and application of V-shaped cuttings removal tool for horizontal wells

摘要:

井筒岩屑床堆积是制约水平井安全高效钻井的主要因素之一，研究表明环空钻井液螺旋流动能够有效提升岩屑清除效率。为此，应用CFD数值模拟与实验的方法设计了一种能够产生环空螺旋流的岩屑床清除工具并进行了现场应用，结果表明：V形叶片对岩屑运移的促进效果及对岩屑床的扰动能力均要强于螺旋形和直棱形叶片，是产生环空螺旋流的首选结构形式；V形叶片的叶片长度存在最优区间，叶片高度越大效果越好，叶片数量影响较弱；现场应用表明岩屑床清除工具在强度、硬度及叶片耐磨性均满足页岩气水平井现场作业要求，工具可随钻破坏并清除岩屑床，结合起钻过程中对岩屑床堆积重点井段进划眼作业，可将顽固性大颗粒岩屑床破坏清除，有效改善井眼清洁效果。

Abstract:

The accumulation of cuttings bed in the wellbore is one of the main factors restricting the safe and efficient drilling of horizontal wells. Research has shown that the spiral flow of drilling fluid in the annulus can effectively improve the efficiency of cutting removal. For this purpose， a rock debris removal tool capable of generating annular spiral flow was designed using CFD numerical simulation and experimental methods， and on-site application was also carried out. The results showed that the promoting effect of the V-shaped blade on cutting transport and disturbance ability on the cutting bed is stronger than that of the spiral and straight edged blades， making it the preferred structural form for generating annular spiral flow. There is an optimal range for the length of V-shaped blades， and the higher the blade height， the better the effect， while the number of blades has a weaker impact. The on-site application shows that the cutting removal tool meets the requirements of shale gas horizontal well operation in terms of strength， hardness， and blade wear resistance. The tool can destroy and remove the cutting bed while drilling. Combined with reaming operations on key sections where the cutting bed accumulates during the tripping process， it can effectively remove the stubborn large particle cuttings and improve the borehole cleaning effect.