带压作业闸板防喷器胶芯动密封性能仿真

发布时间：2018-06-13 04:40

本文选题：带压作业 + 胶芯　；参考：《长江大学》2017年硕士论文

【摘要】：带压作业能够减轻对产层的污染,最大限度地保护原始地层,改善作业环境,同时给油田中后期的稳产带来较大的保障,其独特的优势已经得到业界的普遍认可。闸板防喷器是带压作业设备的核心装置,通过防喷器胶芯的开启和关闭来控制井口密封,实现在线密封,从而完成带压作业过程。因此,闸板防喷器胶芯的密封能力、寿命成为带压作业设备的关键因素。虽然,国内研制的闸板防喷器密封压力越来越高,闸板防喷器压力等级可以达到140MPa,但在带压作业领域利用防喷器进行动密封或旋转作业都存在问题,密封件的寿命也低于国外同类产品的一半。目前国内用于带压作业的闸板防喷器胶芯的动密封压力不大于35MPa,这也制约了国产带压作业装置用于大修、超高压、特殊类型井带压作业的发展。因此研制动密封大于35MPa带压作业闸板防喷器胶芯并使之国产化是十分必要而又刻不容缓。首先,本文通过分析带压作业装置的工作流程,得到带压作业闸板防喷器胶芯的工况条件和载荷特征;同时研究了国内外现有的带压作业闸板防喷器胶芯结构、材料和工作原理。结合工程实际,对现场使用的带压闸板防喷器胶芯进行了力学行为分析,并建立带压作业闸板防喷器胶芯的物理模型;根据流体密封理论和密封准则分析胶芯的静密封机理和管柱运动条件下胶芯的动密封机理。其次,通过对常用的带压作业闸板防喷器胶芯的橡胶材料进行力学性能试验,得到其应力应变曲线,并将实验结果与常用的几种橡胶本构关系进行软件拟合,确定适用于闸板防喷器胶芯的橡胶材料本构模型;然后基于该橡胶材料本构模型,利用ABAQUS软件建立闸板防喷器胶芯密封管柱的静态仿真模型,得到管柱与胶芯在相对静止状态下胶芯的应力分布情况,同时与现场使用的胶芯的失效形式进行比较分析,以验证其正确性;在静态仿真模型基础上,分析井筒压力、活塞杆液压力、橡胶材料等因素对闸板防喷器胶芯Mises应力、接触应力等参数的大小与分布情况的影响规律。探讨带压闸板防喷器胶芯在不同工况条件组合下的静密封性能,从而为胶芯的结构尺寸优化和工况条件选择提供参考。再次,在静态仿真模型基础上,基于胶芯密封机理,建立带压闸板防喷器胶芯密封管柱动态仿真模型,得到管柱相对胶芯上下运动时,胶芯动态密封状态的应力分布规律,并通过与现场使用的胶芯失效形式进行对比分析,判断仿真的可靠性;在动态仿真模型的基础上,分析起下管柱、井筒压力、摩擦系数、管柱运动速度、耐磨块结构参数等因素对闸板防喷器胶芯Mises应力、接触应力等参数的大小与分布情况的影响规律。探讨带压闸板防喷器胶芯在不同工况条件组合下的动密封性能,从而为胶芯的结构尺寸优化和工况条件选择提供参考。最后,基于有限元分析规律,优选胶芯的材料和耐磨块的结构尺寸。得到主要结论如下:(1)Ogden模型最能表征胶芯常用橡胶材料的本构关系。(2)密封面间的接触压力是衡量胶芯密封性能的主要标准。(3)液压封井力不能过大,否则胶芯的Mises应力超过材料的许用应力值,导致胶芯的使用寿命降低;在井筒压力的作用下,橡胶基体密封面上靠近闸板壳体上部区域内的疲劳性损坏最严重;(4)井筒压力是造成耐磨块上部磨损严重的主要因素;管柱与耐磨块圆弧面间的摩擦系数不应过大,否者会加速胶芯的磨损。(5)橡胶基体材料为硬度为75的丁腈和耐磨块参数s为10、k为8、宽度为108时,胶芯可以用于动密封压力不超过35 MPa的带压作业装置。橡胶基体材料硬度为80的丁腈和耐磨块参数s为10、k为8、宽度为108时,胶芯的动密封压力可达50MPa,可以用于动密封压力不超过50MPa的带压作业装置。
[Abstract]:Pressure operation can reduce the pollution of the production layer, maximize the protection of the original formation, improve the operating environment, and bring greater guarantee to the stable production in the middle and late stages of the oil field. Its unique advantages have been widely recognized by the industry. The gate blowout preventer is a core device with pressure operating equipment, through the opening and closing of the blowout preventer core. Controlling the wellhead seal to realize the on-line seal, thus completing the operation process of the belt pressure. Therefore, the seal ability of the gate blowout preventer is the key factor for the pressure working equipment. Although the seal pressure of the sluice blowout preventer is getting higher and higher, the pressure grade of the sluice blowout preventer can reach 140MPa, but it is used in the field of pressure operation. There are problems in the blowout preventer's dynamic seal or rotation operation, and the life of the seal is also lower than half of the foreign products of the same kind. At present, the dynamic seal pressure of the rubber wick used in the sluice blowout preventer is not more than 35MPa, which also restricts the development of domestic pressure operation equipment for large repair, ultra high pressure, and special type of well pressure operation. It is very necessary and urgent to make the brake seal of the brake shoe blowout preventer and make it more domestic. First, through the analysis of the working flow of the working device of the belt press, the working condition and load characteristics of the rubber core of the operation gate are obtained. At the same time, the existing brake plate with pressure operation at home and abroad is studied. The structure, material and working principle of the shotcrete core are made. The mechanical behavior of the rubber core of the blowout blowout preventer used in the field is analyzed in combination with the engineering practice. The physical model of the rubber core of the blowout preventer with pressure operation is established, and the static seal mechanism of the rubber core and the moving density of the rubber core are analyzed according to the fluid seal theory and the seal criterion. Secondly, through the mechanical performance test on the rubber material of the commonly used pressure operation gate blowout preventer rubber core, the stress-strain curve of the rubber material is obtained, and the experimental results are fitted with several commonly used rubber constitutive relations to determine the rubber material constitutive model suitable for the rubber core of the sluice blowout preventer, and then based on the rubber material. The material constitutive model is used to establish the static simulation model of the seal pipe column of the sluice blowout preventer with ABAQUS software, and the stress distribution of the core of the pipe and the rubber core in the relative static state is obtained. At the same time, it is compared with the failure form of the rubber core used in the field to verify its correctness. On the basis of the static simulation model, the wellbore is analyzed. Pressure, hydraulic pressure of piston rod, rubber material and other factors affecting the size and distribution of Mises stress, contact stress and other parameters of the sluice blowout preventer. The static sealing performance of the rubber core of the blowout blowout preventer under different working conditions is discussed, thus providing a reference for the optimization of the size of the rubber core and the selection of the working conditions. On the basis of the static simulation model, based on the mechanism of rubber core sealing, the dynamic simulation model of the rubber core seal of the blowout blowout preventer is established, and the stress distribution law of the dynamic sealing state of the rubber core is obtained, and the reliability of the simulation is judged by the comparison and analysis with the form of the rubber core failure used in the field. On the basis of the dynamic simulation model, the influence of the pipe column, wellbore pressure, friction coefficient, the velocity of the pipe column motion and the structural parameters of the wear-resistant block on the size and distribution of the Mises stress, contact stress and other parameters of the blowout preventer are analyzed. The dynamic tightness of the rubber core in the blowout blowout preventer with different working conditions is discussed. The structure size optimization and working condition selection of the rubber core are provided as a reference. Finally, based on the finite element analysis, the structure dimensions of the material and the wear-resistant block are optimized. The main conclusions are as follows: (1) the constitutive relation of the rubber material used in the rubber core can be characterized most by the Ogden model. (2) the contact pressure between the sealing surfaces is a measure of the glue. The main standard of core sealing performance. (3) the hydraulic sealing ability can not be too large, otherwise the Mises stress of the rubber core exceeds the allowable stress value of the material, which leads to the decrease of the service life of the rubber core; under the action of the wellbore pressure, the fatigue damage of the rubber matrix sealing surface near the upper part of the gate shell is the most serious; (4) the wellbore pressure is caused by the wear-resistant block. The main factor of serious wear is that the friction coefficient between the cylinder and the arc surface should not be too large, or the wear of the rubber core will be accelerated. (5) the rubber matrix material is 75, the parameters s of nitrile and wear resistance block are 10, K is 8, and the width is 108, the rubber core can be used for the belt pressure operating device with the dynamic seal pressure not more than 35 MPa. The parameter s of nitrile and wear-resistant block with the material hardness of 80 is 10, K is 8 and the width is 108, the dynamic seal pressure of the rubber core can reach 50MPa, and it can be used for the belt pressure operation device with the dynamic seal pressure not more than 50MPa.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE931.1

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