Surface Chemical Modification Of NBR And The Tribological And Oil Resistant Performances

Progressing cavity pump (PCP) technology as a new way of oil, compared with otherextraction methods has unique advantages, especially suitable for the oil well of productionhigh viscosity oil, high sand content and high gas content, with low energy consumption,simple structure, high efficiency energy saving, small floor area and so on, widely used athome and abroad and shows the clear upward trend. Conditions of downhole are extremelycomplex, poor working conditions caused the rubber stator badly worn, shorter lifecompared to other key components. Therefore, improving the performance of the rubberstator is one of the key technologies to extend the life of the screw.The most common stator material is nitrile rubber (NBR) currently, copolymer formedby butadiene and acrylonitrile emulsion with excellent abrasion resistance, oil resistance,heat and corrosion resistance, and cheap. At present, more oil fields in our country haveentered into the tertiary oil recovery stage and oil exploration is becoming difficult.Traditional nitrile rubber material is difficult to meet production needs. it urgent need todevelop new rubber material of the stator or modify traditional nitrile rubber material toimprove its performance. In many cases, the rubber material through its surface to participatein the work, and wear and corrosion of the rubber are also start occurs from surface. Improvesurface performance without an overall improvement in the rubber material can significantlyreduce costs and improve economic efficiency.Rubber surface modification improve thecertain performance by changing the surface properties of the rubber on the basis of withoutchanging the nature of the rubber base material.The current study aims at improving the anti-wearing and oil resistant properties ofNBR. Three different halogenation methods (fluorination, bromination and iodations),sulfonation, mixture oxidation, were applied to modify the NBR surface respectively.Related modified formula is designed, and a rubber surface Fluoride-modified experimentaldevice is developed. Through extensive testing systematically study the influence of thevariety and dosage of modifier composition and modification time on the performance ofnitrile rubber, such as surface morphology, hardness, mechanical, etc.Through the frictionand wear and crude oil swelling test on the modified specimen under various conditions to study the relationship between the surface properties and wear resistance, oil resistance ofrubber, and the effects of load, speed, working medium, temperature and other factors on thefriction and wear properties of rubber. With modern testing technology analyze the spectraand infrared spectra of the surface of nitrile rubber before and after the modification, explorefriction, wear reduction mechanism of modified nitrile rubber, and friction chemical reactionoccur in surface modification, friction and wear processes and its impact on the behavior ofthe rubber friction, explore the mechanisms of friction and wear in a variety of real-worldconditions, providing experimental data and theoretical basis for the development of thenitrile rubber material with excellent performance.In order to comprehensively evaluate the quality of modification methods, weconstructed a nitrile rubber surface modification method evaluation system.With thisevaluation system for horizontal comparison between different modification methods andlongitudinal comparison between different proportions with a modified method, objectivelyand scientifically response modification effect of various Nitrile rubber surface modificationmethods and its Scope, make it get concrete and practical applications for different operatingconditions in the production.