【作者】 杨凤艳；

【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， 2014， 博士

【摘要】 螺杆泵采油技术适宜于高粘度、高含砂量原油开采，广泛应用于斜井、水平井、沼泽地区以及海上平台采油作业，具有不存在断杆和管漏故障，相同采油量下能耗低等特点，因此与柱塞式抽油机、电潜离心泵等采油技术相比，适用性更加广泛。近年来在我国辽河、胜利、渤海等油田的应用迅速扩大，为国家的能源开发做出突出贡献。螺杆泵主要是由转子（镀有耐腐蚀层的螺旋状金属杆）和定子（内部衬有橡胶的金属管）部件组成。工作过程中定子橡胶要受到金属转子的冲击以及摩擦。螺杆泵定子橡胶在腐蚀性原油介质中常出现脱胶、撕裂、胶溶等现象，磨损抗力降低，致使设备整体失效。目前，国内外对定子橡胶材料的使役性能研究已经取得了一定的进展，但有关采油井况下橡胶摩擦磨损行为的研究鲜有报道，还处于理论分析阶段。开展这方面的研究工作，一方面可以为不同工况下合理选择螺杆泵定子橡胶材料提供帮助，另一方面也为橡胶摩擦学的发展做出贡献。应用于定子的橡胶多种多样，对比分析材料的物理化学性能、性价比、工作油井的井况等综合因素，主要采用丁腈橡胶（NBR）。丁腈橡胶的性能主要受丙烯腈含量以及炭黑份数的影响。为此，本文将基于不同的采油工况，研究丙烯腈含量、炭黑份数对橡胶耐磨性能的影响，分析其摩擦磨损机理，为不同工况下合理选择定子橡胶材料、提高螺杆泵的使用寿命提供重要依据。论文通过对试验结果的比对分析，归纳出不同工况下丁腈橡胶的摩擦磨损规律。干摩擦下，炭黑份数越高、分散程度越好丁腈橡胶的耐磨性越好。但炭黑份数过高，母胶成分下降，丁腈橡胶的理化性能降低，耐磨性不再随炭黑份数的增加而提高。由于丙烯腈含量的增加，增大了分子链间的极性，丙烯腈含量越高，丁腈橡胶的耐磨性越好。干摩擦下丁腈橡胶的磨损机制以黏着磨损和滞后磨损为主；清水介质下，由于水的冷却作用，降低了温度对摩擦磨损的影响，炭黑份数对磨损量的影响甚微。硬度较小的丁腈橡胶，丙烯腈含量越高，极性越强，耐磨性越好；丙烯腈含量低的丁腈橡胶，若炭黑份数较大，由于-C≡N键少导致分子间作用力小，炭黑更容易分散进入晶格形成柔性网络结构，丁腈橡胶的耐磨性显著增强，丁腈橡胶在水中的磨损机制为磨粒磨损。原油介质下的磨损量略大于水中的磨损量，炭黑份数越高，丁腈橡胶耐磨性越好。低载荷时，由于油膜较厚，磨损主要发生在橡胶与原油之间，因此炭黑份数对丁腈橡胶的磨损性能影响不大；高载荷时，丁腈橡胶与金属轮之间形成动压润滑，磨损量随炭黑份数的增加而减小。硬度较小的丁腈橡胶，丙烯腈含量越高，极性越强，耐磨性越好，丙烯腈对磨损量的影响与水中的磨损规律一致，原油介质中其磨损机制主要是腐蚀磨损。论文通过对干摩擦条件下丁腈橡胶的摩擦磨损行为研究，提出炭黑作用于丁腈橡胶与金属轮摩擦副的摩擦磨损机理。磨损过程中，在剪切力的作用下，炭黑颗粒克服分子间作用力从橡胶基体中脱落，受到挤压在摩擦表面形成润滑膜，减小了基体与对偶面的直接接触，使对偶面的摩擦由橡胶与金属对磨转化为炭黑润滑膜与金属的摩擦，摩擦系数减小，降低了橡胶的磨损。然而，这层润滑膜结合不牢固，非常容易被磨损破坏，橡胶再次受到磨损，炭黑又从内部的基体脱粘重新形成润滑膜，周而复始形成循环。螺杆泵实际工作过程中，定子橡胶的选择需要根据工况的变化而变化，论文实现了基于采油工况的橡胶丙烯腈含量及炭黑份数的最优选择。基于不同炭黑份数下丁腈橡胶摩擦磨损试验结果，确定采油工况、丙烯腈含量、炭黑份数与橡胶耐磨性之间的定性关系，为螺杆泵的橡胶材料选择提供了理论支持。更多还原

【Abstract】 Recent years in our country, technology of oil well using progressing cavity pump isexpanded rapidly in LiaoHe, ShengLi and BoHai sea oils, which has made outstandingcontributions for the country’s energy development. Compared with the plunger typepumping unit, electric submersible centrifugal pump etc, progressing cavity pump issuitable for mining crude oil with high viscosity, high sand content, and deviated well,horizontal well, marshland, and operation of oil production in offshore platform. It is alsono break and pipe leakage failure, low energy consumption under the same oil recovery.Screw pump is mainly composed of stator and rotor (screw) components. Rotor is aspecially processed spiral metal rod, which is coated corrosion resistant layer outside, andthe stator is metal tube with rubber in the internal. In the process of the work, the statorrubber is impacted and slidded by metal rotor. Rubber of screw pump stator often appearthe phenomenon such as degumming, tearing and peptizing in the corrosive medium ofcrude oil, which lead to reducing the wear resistance, then the equipment overall failure,so screw pump stator rubber wear severely restrict the service life of screw pump. Atpresent, the research on the performance of the stator rubber at home and abroad havemade certain progress, which direction is more on the physical and chemical properties ofthe rubber material. But it is rarely reported on friction and wear behavior between therubber and metal pair in the working condition of screw pump, still in the stage oftheoretical analysis. Research work in this area, on the one hand, offer help for reasonableselection of screw pump stator rubber materials under different working conditions. Onthe other hand also contribute to the development of rubber tribology.There are many types of the stator rubber, comprehensive considering the materialperformance, cost-effective, oil well conditions and other factors, people mainly choosenitrile rubber (NBR). Nitrile rubber performance is affected mainly by acrylonitrile andcarbon black content.So in this paper the friction and wear behavior of commonly usedNBR and metals was studied, aimed at offering help to select screw pump stator rubbermaterials for different working conditions. By comparing the test results, friction and wear rule of NBR is summed up underdifferent working condition. Under dry friction, the higher the carbon black content, thebetter the dispersion degree, the better the wear resistance of NBR. But carbon blackcontents are too high, composition of masterbatch decreased, physical and chemicalproperties of the NBR reduced, wear resistance increase with the increase of carbonnumber. With increase of the acrylonitrile content, the polarity between the molecularchains is bigger, the higher the acrylonitrile content, the better the wear resistance ofNBR. The wear mechanism of NBR under dry friction mainly adhesive wear and lagwear; Under water medium, because of the cooling water, reduce the influence oftemperature on the friction and wear, content of carbon black has very little effect onamount of wear and tear. Smaller hardness of NBR, the higher the acrylonitrile content,the stronger the polarity, the better resistance to wear; Low acrylonitrile content of NBR,carbon black content is larger, due to low-C≡N keys, molecular polarity is poor, thepacking is more conducive to form a flexible network structure, to improve the wearresistance of NBR, wear mechanism is abrasive wear in the water. Wear loss under crudeoil medium is slightly larger than the water, the higher the carbon black is leaked,resistance to wear of NBR is better. At low load, due to the oil film thicker, wear mainlyoccurs between rubber and crude oil, so the carbon black content has a little influence onthe wear properties of the NBR; High load, the dynamic pressure lubrication formedbetween NBR and metal wheels, erosion rate decreases with the increase of the carbonblack was leaked. Smaller hardness, the higher the acrylonitrile content, the stronger thepolarity, resistance to wear is better, acrylonitrile affects the quantity of abrasion wearrules consistent with the water, the main wear mechanism is corrosion and wear.Based on research of the friction and wear behavior of NBR under dry frictioncondition, friction and wear mechanism is proposed.Under the action of shear force inwear process, carbon black particles to overcome molecular inter-atomic forces fall offfrom the rubber matrix, by forming a lubrication film extrusion on the friction surface,reduce the substrate, direct contact with the dual surface friction by rubber and metal tomake dual surfaces into carbon black of lubricant and metal friction, the friction coefficient decreases, and reduce the wear of rubber. However, this layer of lubricationfilm combined with the weak, very easy to damage and wear off, rubber wear, has beengiven to the inside of the carbon black and debonding from matrix to form the lubricationfilm, the cycle form a circle.In the screw pump working process, the choice of the stator rubber need variesaccording to the working conditions, this paper realized the optimal selection of NBRbased on the production condition of acrylonitrile and carbon black content. Based on thefriction and wear test results under different carbon black and acrylonitrile content, thequalitative relationship is determined which between production conditions, acrylonitrilecontent, carbon black content and rubber abrasion resistance, it provides theoreticalsupports for screw pump rubber material selection.更多还原