A Real-time Forecasting Method Of Dynamic Liquid Level Calculation Based On The Indicator Diagram Of Pumping Unit Well

Indicator diagram test is an important method to study the working condition of the pumping unit well.Combing the well production data and the indicator diagram data,we can predict the oil production,calculate the dynamic liquid level depth,judge the downhole pump working condition and determine the reasonable pump depth.For a long time,the casing dynamic liquid level of pumping unit well is measured by acoustic sounder which is artificial regular operation.At present the testing methods of oil well includes working fluid acoustic reflection method and the method forecasting the level based on the indicator diagram.Along with the development of oilfield information and the construction of Internet,we have achieved real-time test and remote transmission in the aspect of indicator diagram.The development of the technology put forward higher requirements in terms of the indicator diagram analysis of working condition and the dynamic liquid level test,which makes real-time analysis possible.Based on the ground indicator diagram,dynamic analysis is carried out toward pumping unit system in this paper,and the variation law of suspension point displacement,velocity and acceleration is also studied by using the relevant software,analyzed accurately the inertial load,the friction load,the vibration load and the influence of various downhole factors in the pumping rod movement of the rod pumped well.By establishing the dynamic model of rod,tube,pump fluid system,using the method of Fourier series and finite difference,considering the influence of the sucker rod string along friction loss and the dynamic load,the pump diagram calculation model of rod pumped well is established.And based on the pump diagram to get the data,considering the moving law of ball valves in the process of oil well pump movement,the valve ball switching time in the actual process of oil well pump movement is determined.According to the variation law of pressure and pump load in pump chamber before and after standing valve and traveling valve opening and closing on the pump diagram,Beggs-Brill method is applied to determine the pump intake pressure,Pumping unit well annulus pressure is applied to calculate model,the methods to determine working fluid level is established.Based on theoretical research and field examples,based on VS platform application,a set of well pumping unit working fluid level real-time estimation software were developed with C# program language.