Study on the output metering technology for rod pumped well based on ground dynamometer card

Taking the ground dynamometer card of rod pumped wells as research object, the dynamics model of rod pumped well is updated in terms of rod, tube and fluid, which eliminate the problems of rod deformation, rod viscous damping, effects of column vibration and inertia for rod and liquid and so on. So the pump dynamometer card is obtained which could reflect the working conditions of the pump. Furthermore, combining with automated diagnostic techniques of oil wells, a new curvature calculation model of every point in pump dynamometer card and opening/closing points of values mode are built to propose an algorithm calculation method for effective pump stroke, which realizes the calculation of liquid production. The average relative error between the calculated and measured is 7.25% by using this software to calculate the output 90 oil wells with different cases in Shengli oilfield and Jiangsu oilfield. The actual calculating of dynamometer cards certificates the feasibility of output metering with dynamometer card and can meet the measurement accuracy of output calculation for rod pumped wells.