Rod Pumping System Design And Diagnostic Techniques And Its Application

Sucker-Rod pumping is a kind of artificial lifts that has very strong systematization. The rod pumping system is composed of three parts, layer, wellbore and surface equipment, which must work in phase to make the rod pumping system work with highly efficient and energy-saving, With oilfield development, some producing parameters will change such as layer pressure, gas-oil ratio and water cut etc, which will induce the system uncoordinated work.. So these producing well must be diagnosed to find and redesign the low efficient well, change the swabbing parameter and pumping unit-rod-pump combination.The diagnostic mathematical model combine the kinematical law of pumping unit and the wave equation which describe portrait librating of the pumping rod. The upper boundary condition consider the kinematical law of these pumping unit such as conventional pumping unit, profile pumping unit and the reconstructive energy-saving pumping unit. The torque calculation mathematical model for each type of pumping unit is established. By the computer diagnostic, the work condition of down hole pump and surface facilities can be explained quantitatively to find the low efficiency well, which provide the theory base for optimized design.Based on the three-stage distribution character of the liquid in the annular and used the multiphase method, the mathematical model and the numerical solution about bottle-hole producing pressure is established. According to the liquid distribution character and the mathematical model, the inflow performance relationship (IPR) and down well pressure can be available. Which is the basic for systemic optimized design.The mathematical model of systemic optimized design is established, which take the pump efficiency and Economic Index(EI) as object function .combined American Petroleum institute(API) and wave equation. The critical wave equation is numerically soluted by implicit difference. The pumping rod is designed by API , the wave equation is used to check the security and predictedthe dynamic parameter , The swabbing parameter combination and the equipment of pumping unit ,pumping rod pumping can be available.Based on the former research, the software of the design and diagnosing for the rod pumping system is developed. The correctness of the mathematical model and software are tested by the production data of 42 oil wells in Kelamayi oil field and those low efficient well be redesign. The research result have be successfully applied, economic benefit and energy saving be achieved...