叶片形状对岩屑床清除工具作用效果的影响规律

Analysis on function of cuttings bed remover in different shapes

近年来出现的多种不同结构形状的岩屑床清除工具,能有效提高复杂井的岩屑清除效率,弥补传统岩屑清除方法的不足。现有研究对不同类型岩屑床清除工具作用机理的认识并不完全,制约了其进一步的开发与应用。为了分析不同叶片形状对岩屑床清除工具作用效果的影响规律,采用CFD(计算流体动力学)软件,对3种形状(螺旋形叶片、V形叶片、直棱形叶片)的岩屑床清除工具环空流场的流动特性进行了仿真模拟。结果表明:3种工具都有助于岩屑床的破坏和岩屑在环空中的运移,但不同岩屑床清除工具在井筒流场的压力、速度、涡流特征、岩屑分布方面具有各自的作用特点;在岩屑床清除效果方面,螺旋形和V形岩屑床清除工具强于直棱形。这些都为工具的使用选型和研制优化提供了重要的参考价值。

In recent years,cuttings bed removers in many different shapes are created to promote cuttings transport in the wellbore,which have developed the methods to break and clean cuttings bed,and are proved helpful.However vague understanding on the function of cuttings bed remover limits its further development in our research.In order to distinguish the effects of different tools,three kinds of cuttings removers are designed,including straight rhombus blade,S-shaped blade and V-shaped blade.CFD is used to numerically simulate the drill fluid flow field near cuttings removers and pipes.Simulation results were compared and analyzed in terms of pressure field,velocity field,streamline trajectories characteristics and the distribution of cuttings,thus effect features among tools with different structures are studied.On cuttings bed removal effect,spiral shaped and V shaped tool are better than straight blade,and the former two tools′ effect on the distribution of debris have their own characteristics.These results provide theoretical support for the design,manufacture and field application of cuttings remover.