【作者】 肖阳；

【导师】 刘旭辉；

【作者基本信息】 长江大学 ， 机械工程， 2025， 硕士

【摘要】 随着油气勘探开发向大位移井、长水平段水平井和深层复杂结构井等高难度定向井发展,井下摩阻问题成为制约钻井效率提升的关键因素。液力离合器作为解决该问题的新型技术之一,综合了滑动钻井技术和旋转导向技术的优点,并且具有柔性传动、平衡反扭矩和减小振动等特点。井下液力离合器Hydro Clutch与螺杆泵结构类似,其螺杆传动机构在定向钻进时的运动状态也与螺杆泵相似,但在复合钻进时定、转子均能旋转的运动特性与螺杆泵却有较大不同。当前对井下液力离合器的研究主要集中在稳定工具工作面和减振等方面,对液力离合器中定、转子间运动关系的研究较少涉及。鉴于此,本文以井下液力离合器Hydro Clutch为参考对象,对井下液力离合器中定、转子的运动学,定子衬套力学特性以及结构优化等方面进行深入研究,旨在为提高液力离合器工作性能提供理论支持与设计指导。本文基于无包心法普通内摆线理论构建了螺杆机构定、转子端面型线参数化模型。根据文献中的HNBR材料单向拉伸实验结果,选择了Mooney-Rivlin模型作为定子橡胶衬套的本构模型,并确定了不同温度下的本构模型常数。对工作中螺杆传动机构的定、转子的受力特性进行了分析,并针对定、转子间的接触力建立了接触力学模型。针对液力离合器定向钻进和复合钻进两种工况,分析了定、转子的运动状态,通过运动学分解将转子在定子内的行星运动分解为公转和自转,建立了描述定、转子相对运动的关系式;基于Solid Works Motion进行运动学仿真并选取了转子表面特定点进行了运动学特征监测,结果表明,定、转子运动过程中未发生干涉,验证了螺杆传动机构的运动学模型;转子表面点的运动轨迹呈内摆线特征;当转子表面点、转子中心点和定子中心点三点共线时,转子表面点的线速度取最值,线速度在x、y方向上呈周期性变化。为了研究环境因素,定、转子动态啮合和结构参数等对定子衬套力学特性的影响对定子衬套力学特性展开了分析。结果表明,地层温度和钻井液液柱压力对定子衬套影响显著。定、转子间的动态啮合产生的最大Mises应力和接触压力在“分离”与“结合”不同工况下相差都不超过1%,可认为这两种工况的衬套力学特性具有一致性。系统研究了井深、过盈量、结构参数等因素对定子衬套力学特性的影响,仿真结果表明,定子衬套最大Mises应力随过盈量、摩擦系数、偏心距的增大而增大,随井深、壁厚的增大而减小,随等距半径系数的增大而先减小后增大。为了使定子衬套拥有更长的使用寿命和更好的密封性能,基于响应面法,以过盈量、偏心距和等距半径系数为自变量,以定子衬套最大Mises应力最小值和接触压力最大值为优化目标,建立了拟合的数学模型。分析表明各因素的影响程度依次为:过盈量影响最大,其次为等距半径系数,最小为偏心距。基于响应面法拟合的数学模型,运用NSGA–II优化算法对两种衬套进行多目标优化,得到了结构的优化参数,优化后的常规壁厚型衬套的最大Mises应力下降3%,而接触压力增大了3.9%;优化后的等壁厚型衬套的最大Mises应力下降了7.2%,而接触压力增大了2.4%。对比常规衬套型衬套,等壁厚型衬套在较小过盈量下拥有更好的密封性能。本文通过对井下液力离合器定、转子运动学,定子衬套力学特性以及结构优化的探究,揭示了其运动学特征和衬套力学特性变化规律,完成了螺杆传动机构的结构参数优化,为提高液力离合器工作性能和可靠性提供了建议,也为后续液力离合器相关研究提供了理论依据和技术参考。更多还原

【Abstract】 With the development of oil and gas exploration and development to high-difficulty directional wells such as extended reach wells,long horizontal wells and deep complex structural wells,the problem of downhole friction has become a key factor restricting the improvement of drilling efficiency.As one of the new technologies to solve this problem,the hydraulic clutch combines the advantages of sliding drilling technology and rotary steering technology,and has the characteristics of flexible transmission,counter torque balance and vibration reduction.The structure of the downhole hydraulic clutch Hydro Clutch is similar to that of the screw pump,and the motion state of the screw transmission mechanism during directional drilling is also similar to that of the screw pump,but the motion characteristics of the stator and rotor that can rotate during compound drilling are quite different from those of the screw pump.At present,the research on downhole hydraulic clutch mainly focuses on stabilizing tool face and vibration reduction,and the research on the motion relationship between stator and rotor in hydraulic clutch is less involved.In view of this,this thesis takes the downhole hydraulic clutch Hydro Clutch as the reference object,and conducts in-depth research on the kinematics of the stator and rotor in the downhole hydraulic clutch,the mechanical properties of the stator bushing and the structural optimization,aiming to provide theoretical support and design guidance for improving the working performance of the hydraulic clutch.In this thesis,a parametric model of the stator and rotor end face profiles of the screw mechanism is constructed based on the ordinary inner cycloid theory of the centerless method.According to the uniaxial tensile test results of HNBR material in the literature,the Mooney-Rivlin model was selected as the constitutive model of the stator rubber bushing,and the constitutive model constants at different temperatures were determined.The force characteristics of the stator and rotor of the screw transmission mechanism are analyzed,and the contact mechanics model is established for the contact force between the stator and rotor.Aiming at the two working conditions of directional drilling and compound drilling of hydraulic clutch,the motion state of stator and rotor is analyzed.The planetary motion of rotor in stator is decomposed into revolution and rotation by kinematic decomposition,and the relationship describing the relative motion of stator and rotor is established.Based on Solid Works Motion,the kinematics simulation is carried out and the specific points on the rotor surface are selected to monitor the kinematics characteristics.The results show that there is no interference between the stator and the rotor during the movement,which verifies the kinematics model of the screw transmission mechanism.The motion trajectory of the rotor surface point is characterized by the inner cycloid.When the rotor surface point,the rotor center point and the stator center point are collinear,the linear velocity of the rotor surface point takes the maximum value,and the linear velocity changes periodically in the x and y directions.In order to study the influence of environmental factors,dynamic meshing of stator and rotor and structural parameters on the mechanical properties of stator bushing,the mechanical properties of stator bushing are analyzed.The results show that the formation temperature and drilling fluid column pressure have a significant effect on the stator bushing.The maximum Mises stress and contact pressure generated by the dynamic meshing between the stator and the rotor are not more than 1%under different working conditions of’separation’and’combination’.It can be considered that the mechanical properties of the bushings under these two working conditions are consistent.The influence of well depth,interference and structural parameters on the mechanical properties of stator bushing is studied systematically.The simulation results show that the maximum Mises stress of stator bushing increases with the increase of interference,friction coefficient and eccentricity,decreases with the increase of well depth and wall thickness,and decreases first and then increases with the increase of equidistant radius coefficient.In order to make the stator bushing have a longer service life and better sealing performance,based on the response surface method,the interference amount,eccentricity and equidistant radius coefficient are used as independent variables,and the minimum value of the maximum Mises stress of the stator bushing and the maximum value of the contact pressure are used as the optimization objectives.The fitting mathematical model is established.The analysis shows that the influence degree of each factor is as follows:the interference amount has the greatest influence,followed by the equidistant radius coefficient,and the minimum is the eccentricity.Based on the mathematical model fitted by the response surface method,the NSGA-II optimization algorithm was used to optimize the two bushings,and the optimization parameters of the structure were obtained.The maximum Mises stress of the optimized conventional wall thickness bushing decreased by 3%,while the contact pressure increased by 3.9%.The maximum Mises stress of the optimized equal wall thickness bushing decreased by7.2%,while the contact pressure increased by 2.4%.Compared with the conventional bushing,the equal wall thickness bushing has better sealing performance under smaller interference.In this thesis,through the exploration of the kinematics of the stator and rotor of the downhole hydraulic clutch,the mechanical properties of the stator bushing and the structural optimization,the kinematic characteristics and the variation law of the mechanical properties of the bushing are revealed,and the structural parameter optimization of the screw transmission mechanism is completed.It provides suggestions for improving the working performance and reliability of the hydraulic clutch,and also provides a theoretical basis and technical reference for the subsequent research on the hydraulic clutch.更多还原