Low oil prices push the demand for efficient production, especially in mature fields. The reduction of artificial lifting costs by increasing efficiency is essential for extending the meantime between failure, the economic limit of the reservoir and the increase of the recovery factor.
For achieving these goals, the Finite Elements Method (FEM) is used for modelling and analysing the behaviour of the sucker rod string. Based on the results an optimisation of the whole pumping system is performed, which does not only consider subsurface equipment, but in addition also the surface facilities. The main target is to carry out a diagnostic analysis to evaluate the performance of existing units as well as a predictive analysis to optimize their performance and to design new units.
This paper summarizes the concept and the capabilities of the employed sucker rod pumping system analysis, based on the results of the sucker rod string FEM – simulation, including downhole pump as well as surface unit improvements. The model and the simulation results are verified by a comparison with downhole dynamometer measurements, obtained by several self-developed DDS (Downhole Dynamometer Sensor) during field tests. The presented simulation concept yields more accurate results than currently available commercial software products and in addition allows maximum flexibility in terms of sucker rod string composition, operation conditions, fluid conditions and the choice of installed equipment.
A comparison conducted on the performance and efficiency of a standard pumping system design and an optimized pumping system design resulted in an increased energy efficiency of more than 30%.