Promoting Subsurface Pump Efficiency and Developing Working Conditions of Mechanical Oil Production System by Means of Real-Time Numerical Control Technology

Abstract

Abstract: Both the stroke length and the stroke per minute of the conventional pumping unit remain constant under the given working conditions. Therefore, it is impossible that the working conditions of the surface pumping unit and the subsurface pump are all in a state of the optimum match. The subsequent results are low efficiency of subsurface pump, large impact load, high energy consumption, and low production rate. A new - type N/C primping unit is under development. The Following new technologies are used:— Microcomputer controlling the operation procedure of pumping unit by means of the numerical control technology.— AC frequency conversion and speed regulation technology.— High power and low electricity consumption motor in which the rotor is made of rare earth metal.— Framework for long stroke pumping unit and precision mechanical driving system. The sample pumping Unit is 6m in stroke length. In fact, it is easy to refit into the N/C pumping unit with 10m or longer stroke length. The new type pumping unit is both adjustable at will in the stroke length and stepless variable in the stroke per minute. A cycle movement of the N/C pumping unit consists or the following four processes which are shown by curves:— "S shape" acceleration process at the beginning.— Uniform speed ascending process.— "Reversal S shape" counter direction acceleration process.— Uniform speed descending process. During the whole cycle movement, the computer continuously measures and analyses the holebottom conditions and regulates the movement parameters of the pumping unit, thus enabling necessarily the well to obtain the optimum oil production result. P. 1017^