井下闭环可变径稳定器的设计计算

阐述了井下闭环可变径稳定器的结构和工作原理 ,分析了影响可变径稳定器性能的钻井液驱动力、活塞密封阻力、复位弹簧弹力等因素 ;并对可变径稳定器中关键部件可调稳定块进行了静力学分析 ,推导出可调稳定块保持稳定平衡所需钻井液驱动力计算公式 ,为类似井下工具设计提供了理论依据。现场试验结果表明 ,新设计的井下闭环可变径稳定器结构比较合理 ,功能比较完善 ,可自动无级变径 ,达到了安全、平稳、高效、智能的目标 ,是钻大位移井的有力工具

Design and calculation of downhole close-loop adjustable stabilizers

The design feature and operating principle of the downhole close-loop adjustable stabilizer are described. The factors influencing the performance of the stabilizer are analyzed, including the drill fluid driving force, piston seal resistance and the elasticity of the reset spring. Statics analysis of the adjustable stabilizing block is made, and the equation for calculating the drill fluid driving force needed for keeping stable balance of the stabilizing block is derived, providing a theoretical basis for the design of similar downhole tools. Field test shows that the newly-designed downhole close-loop adjustable stabilizer has reasonable structure, powerful function, and can be adjusted automatically and steplessly, therefore it is one of the reliable tools for drilling extended-reach wells.