石油学报 ›› 2018, Vol. 39 ›› Issue (11): 1299-1307.DOI: 10.7623/syxb201811010

• 石油工程 • 上一篇    下一篇

低产抽油机井动态参数仿真模型与提高系统效率的途径

王宏博1, 董世民1, 甘庆明2,3, 辛红3, 朱葛1   

  1. 1. 燕山大学机械工程学院 河北秦皇岛 066004;
    2. 长江大学石油工程学院 湖北荆州 434000;
    3. 中国石油长庆油田公司油气工艺研究院 陕西西安 710021
  • 收稿日期:2017-12-10 修回日期:2018-08-22 出版日期:2018-11-25 发布日期:2018-12-10
  • 通讯作者: 董世民,男,1962年8月生,1983年获大庆石油学院学士学位,1998年获西南石油学院博士学位,现为燕山大学教授、博士生导师,主要从事机械采油系统动态仿真与运行优化的研究。Email:ysudshm@163.com
  • 作者简介:王宏博,男,1992年2月生,2015年获燕山大学学士学位,现为燕山大学博士研究生,主要从事机械采油系统动态仿真与运行优化的研究。Email:wang620138@stumail.ysu.edu.cn
  • 基金资助:

    河北省自然科学基金项目(E201703101)和国家自然科学基金项目(No.51174175)资助。

Dynamic parameter simulation model of low-production pumping well and the ways to improve system efficiency

Wang Hongbo1, Dong Shimin1, Gan Qingming2,3, Xin Hong3, Zhu Ge1   

  1. 1. College of Mechanical Engineering, Yanshan University, Hebei Qinhuangdao 066004, China;
    2. School of Petroleum Engineering, Yangtze University, Hubei Jingzhou 434000, China;
    3. Research Institute of Oil and Gas Technology, CNPC Changqing Oilfield Company, Shaanxi Xi'an 710021, China
  • Received:2017-12-10 Revised:2018-08-22 Online:2018-11-25 Published:2018-12-10

摘要:

综合考虑柱塞运动规律、阀球运动规律、阀隙瞬时流量与油井流入特性等因素的影响,建立了流体进泵规律与泵筒内瞬时压力的仿真模型,以此为依据改进了抽油杆柱纵向振动底部边界条件的仿真模型,进而建立了基于抽油杆柱纵向振动与流体进泵规律耦合的抽油机井示功图动态仿真模型;基于流体瞬时进泵规律,建立了抽油泵充满系数、漏失系数的仿真模型,从而改进了排量系数计算模型。对比仿真结果表明,所建立的系统动态参数仿真模型具有通用性,可以提高低沉没度供液不足油井示功图、排量系数与系统动态参数的仿真精度。仿真优化算例表明:①大泵径、长冲程与低冲数的抽汲参数设计原则仍然适用于低产抽油机井的节能设计,但最低冲数存在界线,同时最低冲数界限也限制了泵径上限;最低冲数界限随泵间隙的增加而增加;②对于严重供液不足油井,通过合理降低冲程与冲数,可以确保在油井产液量下降率低于5%的条件下,使系统效率最高提高近120%;③在油井产液量一定、下泵深度相同的条件下,优化冲程、冲数与泵径组合可以显著提高系统效率,仿真算例的系统效率变化范围为9.43%~17.48%;④在油井产液量与流压一定条件下,综合优化下泵深度、冲程、冲数与泵径可以显著提高系统效率,优化算例的系统效率由10.56%提高到31.49%。

关键词: 低产抽油机井, 抽油杆柱振动, 流体进泵规律, 耦合动力学, 排量系数, 节能分析

Abstract:

Through comprehensively considering the influences of piston motion law, valve ball movement law, instantaneous flow rate of valve clearance, oil-well inflow performance and so on, this study establishes the simulation model on the laws for pumped fluid flow and the instantaneous pressure in pump barrel. Accordingly, the simulation model on the bottom boundary condition of longitudinal vibration of sucker rod stem is improved. Further, this study sets up the dynamic simulation model of dynamometer card for pumping well based on the coupling between the longitudinal vibration of sucker rod stem and the laws for pumped fluid flow. As per the laws of instantaneously pumped fluid flow, a simulation model on the fullness and leakage coefficients of oil pump is established to improve the calculation model of discharge coefficient. Through comparing the simulation results, it is shown that the created system dynamic parameter simulation model is generic, able to improve the simulation precision of the dynamometer card, discharge coefficient and system dynamic parameters of oil wells with low submergence depth and insufficient liquid supply. The simulation optimization cases show that (1)the design principle of swabbing parameters for large pump diameter, long stroke and low stroke frequency is also applicable to the energy-saving design of low-production pumping well, but there is a limit of minimum stroke frequency. Meanwhile, minimum stroke frequency also limits the upper limit of pump diameter, and the limit of minimum stroke frequency increases with the increasing pump clearance. (2)For oil wells with insufficient fluid supply, when the liquid-production drop rate is less than 5%, the system efficiency can be increased up to 120% by reducing the stroke and stroke frequency reasonably. (3)Under the condition of certain liquid production and equivalent pump depth for oil wells, system efficiency can be improved significantly by optimizing stroke, stroke frequency and pump diameter, and the system efficiency of simulation case varies from 9.43% to 17.48%. (4)Under the condition of certain liquid production and flow pressure, comprehensive optimization of pump depth, stroke, stroke frequency and pump diameter can significantly improve system efficiency, and the system efficiency of the optimized case is increased from 10.56% to 31.49%.

Key words: low-production pumping well, vibration of sucker rod stem, laws for pumped fluid flow, coupling dynamics, discharge coefficient, energy saving analysis

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