Power Diagram Data Acquisition And Power Diagram Measurement Of Rod Pumping Unit

Accurate measurement of oil well fluid production can improve fluid production efficiency,save collection costs,and provide a guarantee for oilfield production decision-making and management.The use of the work diagram method to measure the amount of liquid produced has the characteristics of low cost and convenient operation,which improves the measurement efficiency and saves the time used for measurement.Because the traditional work diagram will be affected by the deformation and vibration of the sucker rod,and by the inertial force and friction force,there will be a large deformation,and the liquid production cannot be accurately measured.Therefore,the thesis adopts the effective stroke method of pump power diagram to measure the liquid production.The pump work diagram eliminates the influence of rod string vibration,elastic deformation,inertial force and other factors,can more truly reflect the working conditions of the downhole pump and the effective stroke of the plunger,and improve the accuracy of the work diagram measurement.The main research content includes the following aspects:Research and design the load and displacement data collection of rod pumping system.Load and displacement data are the basic elements of the shape success diagram,which directly affects the effect of the work diagram.In order to collect good-quality data,the corresponding relationship between the working principle of each part of the pumping system and the indicator diagram is studied,and the bayonet-type polished rod load sensor and acceleration sensor that are convenient to install are selected to obtain the power diagram data;A data acquisition device is designed to perform circuit conditioning on the collected sensor signal and transmit it to the host computer to ensure the stability and accuracy of the data source.The method of converting the ground power diagram into the downhole pump power diagram is studied.Taking the sucker rod as the research object,through the overall force analysis of the sucker rod and the force analysis of the micro-element method,combined with Hooke’s law of elasticity,a one-dimensional Gibbs wave equation is established,and the initial conditions and upper and lower boundary conditions are combined to form a complete Model of the pumping system.The Fourier series expansion method is used to express the upper boundary conditions,the Fourier coefficients are solved,and the load displacement function at any section is obtained.The conversion of the work diagram is completed,and a pump work diagram that can truly reflect the pump condition is obtained.Research the extraction method of effective stroke.By analyzing the pump power diagram and the position of the valve opening and closing point,the difference between the position of the fixed valve opening and closing point and the position difference of the moving valve opening and closing point is regarded as the displacement of the plunger relative to the pump barrel,and the two displacements The smaller value is the effective stroke of the plunger.According to the wellhead fluid production formula,the effective stroke is used to realize the measurement of wellhead fluid production.The pump work diagram can truly reflect the downhole working conditions.The liquid production calculated by the effective stroke of the pump work diagram is compared with the liquid production calculated by the ground work diagram,Using the effective stroke method of the pump work diagram to measure the liquid output greatly improves the accuracy.