The Optimum Design For The Sucker-rod Pumping System

The oil extraction method with sucker-rod pumping system is the most pioneer and extensive manual uploading oil extraction method. The rod pumping system should also include the design interrelated design software, besides the hardware, such as the pump, the sucker-machine, and the sucker-rod. So it need perform research on the sucker-rod pumping system to meet the producing demand from the oil field. The design for the sucker-rod pumping systems has gone through the period as long as the petroleum industry. With the progress of the technology, the design enters intoa new period with the whole petroleum industry, commencing the more veracious and optimum design.This paper integrates the engineering fact, founding models for calculating and analyzing, including the thereinafter several aspect:This paper founds a model for load on a rod in deviated well, according to the theory of rod designing put forward by American Petroleum Institute, doing research on the program realization of the designing sucker-rod. With the log data processing, it uses cubic interpolation and minimum curvature radius method to do with the log data.It designs the programming for the API RP 11L. It chooses the vitta, the pump, and the sucker-rod assemblage in reason from the dimensionless quality curve, and the sucker-rod assemblage sheet. In the process, it scatters the six groups dimensionless quality curves, and later uses the different interpolation according to the characteristic of every curve to implement. By design formuleas of equivalent elastic midulus, equivalent volume density, equivalent stiffness and natural frequency, to design mixed sucker-rods.It adopts the variable step length scheme to evaluate at the connection point, and adopts the implicit difference scheme to evaluate in the same rod. By using this method, it can evaluate the displacement and the load of any section at any time, and the method is stable, and it is especial adapt to the inclined well.The axial load and centralizer spacing from the bottom to the top are calculated by using the mechanical analysis method and the log data. By assuming the rod string contacting with the tubing string only at the centralizers, the rational centralizer spacing, the axial force and lateral force on the upper centralizer are determined by means of setting up a nonlinear equation and calculated by using step-by-step scanning combined with the Brent arithmetic.The optimal design model of downhole pump depth and rod string assemblage is set up. The paper chooses the golden section searching arithmetic with the Brent arithmetic to do the design.