【作者】 王哲；

【导师】 王世杰； 吕晓仁；

【作者基本信息】 沈阳工业大学 ， 机械设计及理论， 2013， 博士

【摘要】 潜油螺杆泵采油系统作为一种实用有效的机械采油设备，具有结构简单、体积小、耗能低、投资少，以及使用、安装、维修、保养方便等特点，它兼有离心泵和柱塞泵的优点，适宜于斜井、水平井、沼泽地区以及海上平台采油作业，且不存在断杆和管漏故障等，并在高粘度稠油、大油气比油和含砂油的开采作业中体现出了较好的性能和效益。目前，该技术在国内外油田已得到了普遍重视，并有望成为油田主要机采方式之一。橡胶材料因具有良好的耐油、耐磨和耐高温等性能，被用来作为采油螺杆泵的定子材料，由于油井实际工况环境常为掺杂磨粒的腐蚀性介质，使动态密封过程中的橡胶材料易发生过早的磨损失效，极大地影响了螺杆泵橡胶定子的使用性能和工作寿命，这也是导致螺杆泵失效的主要原因之一。然而，迄今为止尚缺乏为选择此类橡胶材料所必须的磨损机理研究和普适性指导原则。因此，研究采油螺杆泵定子橡胶的磨损机理，不仅对生产有实际应用价值，也将十分有益于丰富和发展橡胶摩擦学理论与实践知识。针对现今采油螺杆泵定子橡胶磨损机理研究不足的问题，本文以采油螺杆泵的金属转子与橡胶定子摩擦配副为研究对象，在实验室中模拟螺杆泵实际工况，建立定子橡胶磨损试验分析程序，构建试验平台，对橡胶试块在除砂原油润滑介质、含砂原油介质及液体石蜡润滑等条件下进行磨损试验。从磨粒磨损、侵蚀磨损以及腐蚀磨损等方面对采油螺杆泵定子橡胶摩擦磨损行为进行较全面的研究。首先基于对采油螺杆泵工作特性的充分认识，详细分析了螺杆泵螺杆在橡胶衬套副中的运动特性，推导出单螺杆泵转子与定子间的最大滑动速度以及接触压力计算公式。根据采油螺杆泵运动学的分析方法及计算公式，以GLB120-27型采油螺杆泵的结构参数为例，确定金属转子和橡胶定子间的滑动速度和载荷数据范围，进而确定了实验室环境下模拟螺杆泵工况条件的磨损试验中钢轮的转速和载荷参数值。论文阐述了橡胶摩擦磨损的复杂性，探讨了原油在螺杆泵定子橡胶摩擦磨损过程中的影响及基本润滑机理，并深入分析了橡胶摩擦磨损理论，明确了除砂原油介质中螺杆泵定子橡胶的摩擦磨损行为、橡胶摩擦磨损主要机理、磨损类型及其影响因素。在此基础上通过对采油螺杆泵定子橡胶本身的材料性能和使用环境进行分析，系统地研究含砂原油介质中螺杆泵定子橡胶的磨损行为及其机理。研究发现，采油螺杆泵正常工作中的磨损形式主要有磨粒磨损、侵蚀磨损、疲劳磨损及腐蚀磨损等。针对这些磨损行为，采用MPV-600型微机控制磨粒磨损试验机，选取常用的丁腈橡胶（NBR）和氟橡胶（FPM）试块与45#钢在除砂原油润滑、原油含砂介质以及液体石蜡润滑条件下进行采油螺杆泵定子橡胶衬套副的摩擦磨损模拟试验，测定其摩擦系数和磨损量，分析得到摩擦系数和磨损量随法向载荷的变化规律，再利用扫描电子显微镜（SEM）、X射线能量色散光谱分析仪（EDX）以及红外光谱分析仪（FT-IR）对橡胶磨损后的磨痕表面、化学元素含量和官能团状态进行测定。综合试验测试结果，分析橡胶的摩擦磨损行为，观察除砂原油润滑条件下橡胶的物性变化，考虑含砂原油中磨粒浓度、尺寸、形状在不同法向载荷作用下对橡胶的磨损规律，以及关注腐蚀性介质对橡胶磨损的影响，进而得到橡胶定子在原油介质中的磨粒磨损机理以及溶胀腐蚀和机械磨损的交互作用的表达关系，并针对现有的橡胶磨损试验机的不足进行改进，设计新的含砂料浆橡胶磨粒磨损测试装置。通过上述研究，能够较全面地阐述采油螺杆泵定子橡胶的磨损机理，为定子橡胶在实际工程应用中的摩擦学设计、材料选择、性能评价提供指导性原则。更多还原

【Abstract】 As a new practical and effective mechanical oil recovery device, PCP has uniqueadvantages including simple connfiguration, small size, low noise, low energyconsumption, and less investment. PCP is also characterized by easy use, quick installation,convenient repair and maintenance. It has the merits of both the centrifugal pump and thepositive displacement pump. Free from broken rods and tube leakage, it is well used for theinclined shaft, horizontal wells, and the operations of oil production in the marsh land andoffshore platform. The better performance and higher efficiency of PCP is achieved in thedrilling operations of high viscosity heavy oil, big oil-gas ratio oil and sand oil. At present,PCP has received widespread attention at home and abroad, and is expected to become themain method for machinery oil production. The rubber material, characterized by good oilresistance, abrasion resistance and high temperature resistance, is used as the material ofPCP’s stator. The actual working environment of oil wells is usually filled with thecorrosive medium with abrasive grain dopants, making rubber materials prone topremature fatigue wear failure in the dynamic sealing process. This tendency greatlyaffects the PCP’s stator performance and working life, and therefore becomes one of themain causes of PCP failure. To date, unfortunately, few studies has been performed on thewear mechanism of such rubber material, and no general guiding principles have beenestablished either. Research on PCP’s stator rubber wear mechanism, therefore, not onlyhas a certain value to the actual production, but is also of crucial significance to theenrichment and development of rubber tribology theory and practice.In response to inadequate research on PCP’s stator rubber wear mechanism, this paper,based on the testing of abrasive wear, abrasive grain erosion wear and corrosion wear,conducts a comprehensive study on friction-wear mechanism of oil screw pump statorrubber. To achieve this goal, rubber friction and wear tests were made. In the tests, PCP’smetal rotor and stator of metal rubber friction were used as the test subject, and the actualworking condition of PCP was simulated in the laboratory. After the stator rubber frictionand wear test analysis program was designed and the test platform was built, rubberfriction and wear tests were conducted with rubber blocks placed under oil lubricationconditions, oil and sand medium conditions and lubrication of liquid paraffin conditions.At first, on the basis of the full understanding of the characteristics of PCP, a detailedanalysis of the motion characteristics of PCP’s screw in the rubber bushing pair was made, and then the formula of the maximum slip velocity of single screw pump rotor and stator aswell as the formula of contact pressure between rotor and stator were derived. According tothe structure parameters of GLB120-27type PCP, the sliding velocity and load databetween PCP’s rotor and rubber stator were obtained through the PCP’s kinematics analysismethod and calculation formula, thus establishing the speed and load parameters of rubberwear under the simulated conditions of PCP’s actual working conditions in the laboratory.This dissertation expounds the complexity of friction and wear of rubber, discussesthe lubrication mechanism and the impact of crude oil in the screw pump stator rubberduring friction, in-depth analysis of the rubber friction and wear theory, clear the crude oilmedium in screw pump stator rubber friction and wear process, rubber friction and wearmechanism, wear type and its influencing factors. On this basis, through the analysis aboutthe screw pump stator rubber material properties and the working environment, systematicresearch the wear mechanism in crude oil screw pump stator rubber.The study finds that during the early phase of PCP’s running, the main forms of wearin the normal working of a screw pump include abrasive wear, adhesive wear, abrasivegrain erosion wear, fatigue wear and corrosive wear. To study these wear behaviors, afriction wear test was conducted on MPV-600micro-computer-controlling grain-abrasiontesting machine. NBR, FPM and45#steel pair area were tested in the conditions of crudeoil lubricating, sand-contained crude oil lubricating and liquid paraffin lubricating.Through the measuring of the friction coefficient and wear volume, the variation pattern offriction coefficient and wear volume with normal load was established. Then with the aidof SEM, EDX and FT-IR, the wear scar surface, functional group state and chemicalelement contents of rubber were measured after wear occurred. Based on the above testresults, this dessertation analyzes rubber’s friction and behavior, observes the physicalchanges of rubber in oil medium, considers the grain concentration, size, shape at differentnormal loads on the rubber wear in crude oil, and pays attention to the influence ofcorrosive medium to rubber wear. Thereby, this dessertation discovers relevance of theinteraction effect between rubber stator’s abrasive wear mechanism in oil medium, andimmersion corrosion and abrasive wear. And make improvements for the deficiencies ofthe existing rubber abrasion testing machine, set up a new rubber sand slurry abrasive weartesting device.The research in this dissertation comprehensively expounds the mechanismof wears of the PCP stator rubber and provides guiding principles for stator rubber in theactual engineering application in tribology design, material selection and performance evaluation.更多还原