煤层气井排采系统有杆泵运行特性分析  

Operating Performance of Sucker Rod Pump for the Pumping System in Coalbed Methane Wells

作　　者：刘新福[1] 刘春花[2] 綦耀光[2] 

机构地区：[1]青岛理工大学机械工程学院,青岛266520 [2]中国石油大学(华东)石油石化装备新技术研究中心,青岛266580

出　　处：《机械工程学报》2017年第8期195-200,共6页Journal of Mechanical Engineering

基　　金：国家科技重大专项(2011ZX05038);泰山学者工程专项经费(ts201511038);山东省重大关键技术(2016ZDJS02A15)资助项目

摘　　要：煤层气井低沉没度下泵的运行特性和气水两相流中的动态充满度直接影响到有杆泵的工作优劣,对保证有杆排采系统的正常工作具有重要意义。基于泵阀动力学和水力摩阻分析,建立有杆泵泵阀动态特性数学模型,依据数值求解并结合泵阀开启试验测试结果,得到低沉没度时泵阀的动态特性和顺利开启的临界沉没度条件,同时依据气液两相流数值求解和泵运行特性试验测试结果,分析出泵筒动态充满度变化规律及合理沉没度时泵高效运行条件。结果表明,泵阀开启瞬间阀球的水力摩阻较大,其幅值周期波动的频率较快且在短时间内迅速变小后趋向平稳;泵阀水力摩阻和临界沉没度随冲程冲次的增大而提升,冲次由2.0 min^(-1)调为6.6 min^(-1)后,临界沉没度由2.55 m升至3.05 m;减小冲次和气液比及增大泵入口压力会显著提升泵筒内液位和充满度,且气液比的影响最为显著;提升沉没度会使泵效先迅速增大,达到70%~80%时出现拐点而后增长缓慢,煤层气井主要泵型的临界沉没度通常介于3.0~6.0 m,而合理沉没度需达到15.0~20.0 m以上,以维持高效运行。The operating characteristics under low submergence depth and dynamic volumetric efficiency in the two phase gas and water flow will affect the pump performance and provide an important basis for the normal operation of sucker rod pumping system in the coalbed methane （CBM） wells. The mathematical model of dynamic performance for pump valve is developed based on valve dynamics and hydraulic friction. The operating performance and critical submergence depth are given due to the numerical solution and test results of valve open. And the variation of dynamic volumetric efficiency and efficient operating condition of sucker rod pump under reasonable submergence depth are analyzed based on the numerical solution and test results of operating performance. The results show that the hydraulic friction of pump valve is high during the opening moment. Its fluctuating frequency is fast and its amplitude quickly decreases in short time then becomes stable. The critical submergence depth increases from 2.55 m to 3.05 m while the pumping speed rises from 2.0 min-lto 6.6 min-1. The decrease of pumping speed and ratio of gas to water and increase of inlet pressure will enhance the water level and volumetric efficiency in pump. Furthermore, The increase of submergence depth will rise the pump efficiency rapidly, and then the pump efficiency increases slowly while it reaches to 70%-80%. The critical submergence depth is typically between 3.0 m to 6.0 m while the reasonable submergence depth is more than 15.0 m to 20.0 m in order to operate with high efficiency for the most pumps in the CBM wells.

关 键 词：煤层气井 有杆泵 运行特性 动态充满度 合理沉没度 

分 类 号：TE933[石油与天然气工程—石油机械设备]