水力诱振式双向耦合连续管减阻器设计

连续管刚度小,在下入或加压钻进过程中容易屈曲,导致摩阻增大甚至锁死。为此,基于附壁效应和卡门涡街效应,创新设计了可诱发连续管轴向与径向振动的水力诱振式双向耦合连续管减阻器。该减阻器通过流体诱发持续振动,将连续管与井壁间的静摩擦转化为滑动摩擦;涡轮动力源、径向振动组和流体振动腔室的多级耦合产生轴向冲击力,克服了连续管与井壁之间的摩阻,避免了纯机械式减阻器振动间断以及动力源驱动复杂等缺点。利用有限元软件进行减阻器径向振动组模态分析,分析结果表明:其固有频率远大于工作频率,避免了共振导致的结构破坏。在轴向冲击力测试试验中,该减阻器在10、14和18 L/s的注液排量下可分别产生23.3、30.1和34.6 kN耦合轴向冲击力,随着注入流量的线性增加,轴向冲击力呈非线性增大。应用该减阻器可增大连续管在水平段的延伸范围。

Design of Hydraulic Induced Bidirectional Coupling Coiled Tubing Drag Reducer

The low rigidity of the coiled tubing makes it easy to buckle during running or drilling,which leads to increased drag and even locking.To address the problem,based on the Coanda effect and the Carmen vortex effect,a hydraulically induced bidirectional coupling coiled tubing drag reducer that can induce axial and radial vibration of the coiled tubing was designed.The drag reducer converts the static friction between the coiled tubing and the well wall into sliding friction by inducing continuous vibration through fluid.The multi-stage coupling of the turbine power source,radial vibration modular,and fluid vibration chamber generates axial impact force,which reduces the friction between the pipe and the wellbore wall,and eliminates the shortcomings of mechanical drag reducer like vibration interruption and complicated power source driving.The finite element software was used to perform the modal analysis of the radial vibration modular of the drag reducer.The analysis results show that its natural frequency is much greater than the operating frequency,which avoids the structural damage caused by resonance.In the axial impact force test,the drag reducer can produce 23.3 kN,30.1 kN and 34.6 kN coupled axial impact force at 10 L/s,14 L/s and 18 L/s injection displacement.With the increase of injection flow,the axial impact force increases nonlinearly.The application of the drag reducer can increase the extension range of the coiled tubing in the horizontal section.