Research On Automatic Speed Control Technology Of Rod Pumped Units

Based on the automatic control technology of remote online monitoring data, this paper studied on how to maintain efficient production by controlling the inverter and making stroke adjustments timely. The stroke was determined by the relationship between the reservoir fluid supply capacity and pumping discharge capacity. So this paper studied the relationship between the testing data(e.g. indicator diagram, input power) and performance parameter(e.g. well productivity, system efficiency, dynamic liquid level, pump filling degree). The main contents are listed as follows: First, Adjusting the working conditions based on the real-time measurement of indicator diagram of ground wells. After indicator diagram which was solved by the Gibbs method was normalized after treatment, five-point method was used to calculate the curvature of the points to identify the two points with the largest change of the curvature of the up stroke and down stroke as the opening and closing point. Effective stroke with the minimum two-stroke position was used to determine the full extent of the pump, thus getting the well productivity calculation formula based on the amount of fluid pump efficiency factors. Second, analyzing the relationship between stroke and system efficiency based on the system efficiency calculation model. Third, analyzing the force conditions of sucker rods and oil well pump, then deducing dispatched liquid formula, giving the well fluid level calculation steps. Based on the above study, this paper established three types of pumping automatic control theory models with restrictions of oil well production, system efficiency, dynamic liquid level or pump filling degree and developed pumping automatic control device which has achieved good field application results.