煤层气井有杆泵排采设备悬点载荷变化规律  

Variation of Polished Rod Loads for Sucker Rod Pumps in Coalbed Methane Wells

作　　者：刘新福[1] 綦耀光[1] 胡爱梅[2] 韩军 杨磊[1] 

机构地区：[1]中国石油大学机电工程学院,东营257061 [2]中联煤层气国家工程研究中心,北京100095 [3]中石油煤层气有限责任公司,北京100011

出　　处：《机械工程学报》2011年第15期127-134,共8页Journal of Mechanical Engineering

基　　金：国家科技重大专项(2011ZX05038-002);中国石油大学研究生创新基金(CXZD11-09)资助项目

摘　　要：煤层气井悬点载荷是标志排采设备工作能力的重要参数。基于有杆泵设备运动特性分析,建立计算悬点各载荷的数学模型和动力示功图,并通过现场实例验证,给出悬点载荷的变化规律和杆管变形情况。结果表明,煤层气井悬点载荷的计算需要考虑振动载荷和摩擦力的影响;抽排初期的强排水使悬点载荷变化幅值加大,稳定生产后,其变化较小;煤层气井动载荷和摩擦载荷所占的比例较大,分别达到15%和5%,这就加大悬点载荷的变化幅度与不平衡性,开采中,静载荷所占比例逐渐增大,而动载荷所占比例迅速减小,稳定生产时仅为2.5%,此时摩擦力的比例稳定在3.7%左右;另外,排采设备的杆管总变形量较小,仅占冲程的10%左右,其中静变形量占较大比例,而惯性载荷引起动变形量较小,后期可忽略。该算法首次较为准确地计算出煤层气井有杆泵悬点载荷并用动力示功图直观表达,为排采设备的设计和选型提供了合理依据。Polished rod load is an important parameter to illustrate the operating potential of sucker rod pumping system.Based on the kinetic characteristic of the pump,the mathematical models of polished rod loads and dynamometer cards are obtained in coalbed methane（CBM） wells.Then the variation of polished rod loads and the string deformation are developed by applying the method.The results show that the computation of polished rod loads should consider the vibration and friction loads.The variation range of polished rod load is large due to the heavy water drainage during the prophase while it is small during the steady flow production.The dynamic and friction to polish rod load ratios are calculated to be 15% and 5%,respectively,which increases the variation range.The static load ratio enhances gradually,and the dynamic load ratio decreases rapidly during the prophase and is just 2.5% during the steady flow production,while the friction load ratio becomes 3.7%.Besides,the total string deformation in CBM wells is just 10% of stroke length,which is much smaller than that in oilfields.And the static deformation is relatively large while the dynamic deformation is small in the total deformation.A mathematical model and dynamometer card for the sucker rod pumping system as the result of this work will provide the reasonable basis for designing and selecting sucker rod pumps.

关 键 词：有杆泵 悬点载荷 动载荷 摩擦载荷 示功图 

分 类 号：TH123[机械工程—机械设计及理论] TE933[石油与天然气工程—石油机械设备]