有杆抽油系统地面示功图在井下故障诊断中的研究

Surface Dynamometer of Rod Pumping System in Downhole Fault Diagnosis

目前机械式采油仍是在国内外原油开采中占首要地位,而有杆抽油系统又是机械采油中应用最广的。抽油泵在井下的工况十分复杂,工作环境极其恶劣,不但受"机、杆、泵"抽油设备的影响,而且直接受到"砂、蜡、气、水"的影响,故障发生率很高。我们应用波动方程,建立了以泵示功图为基础的井下故障诊断模型,边界条件选用光杆动载荷及位移得到抽油杆柱任意截面处的载荷和位移计算表达式,进一步利用计算机编程绘出所需的抽油杆各截面及泵的示功图,实现了悬点示功图到井下泵示功图的转换,并通过示功图对泵的漏失、受气体影响、磨损、卡泵等工作状况做出分析,达到对抽油系统的整个工作状况进行评价的目的。

Currently mechanical recovery still occupies a dominant position in domestic and foreign crude oil production;rod pumping system is most widely used in mechanical recovery.The working condition of downhole pump is very complex;it is not only affected by the pumping equipment,such as machine,rod,and pump,but also influenced by sand,wax,gas and water,and results the high incidence of failure.We build the downhole fault diagnosis model based on dynamometer by applying the wave equation,boundary condition of rod dynamic load and displacement is used to get the load and displacement expression of arbitrary rod cross-section,and use computer to program and obtain the dynamometer of required rod cross-section and pump,and realize the conversion of rod dynamometer to downhole pump dynamometer;the loss of pump,gas influence,wear and tear is analyzed through dynamometer to evaluate the working conditions of the pumping system.