METHOD FOR CONTROL OF SUBSURFACE PUMPING UNIT IN OIL WELL Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: this can be used in control for operation of oil wells equipped with subsurface sucker rod pumping units. According to method, controlled is changing of forces at point of suspending pumping rods. Preset according to method of control is dynamic level of liquid in well bore to be above level of pump sucking. Coming under control are periodic disengagements of pumping unit for accumulation of liquid. Additionally subjected to control is driving motor rotation speed. Measured are positions of polished rod included in string of pumping rods and calculated is its extreme upper position and its extreme lower position. At moments of approaching extreme upper position and extreme lower position of rod stroke, driving motor is smoothly stopped and delay is undertaken in these positions during 1-2 s. On expiration of delay periods, driving motor is smoothly started. Values of forces are recorded before smooth starting of driving motor and at moment of changing direction of rod movement after its starting. According to recorded values of forces, calculated are average values of forces at extreme upper position and extreme lower position of pumping rod. Then, determined is dynamic level of liquid according to formula given in description of invention. Application of method of control improves reliability of control and operation of entire subsurface sucker rod pumping unit. EFFECT: higher efficiency. 1 dwg