EFFICIENCY IMPROVEMENT OF DUAL COMPLETION BY ROD PUMP AND ELECTRIC CENTRIFUGAL PUMP UNITS

Abstract

Background The introduction by the oil companies of programs energy efficiency and increasing the profitability of oil field development in modern market conditions causes the wide spread of dual completion technology using pumping units. Oil production by rod units, including rod and electric centrifugal pumps, is one of the most common ways of developing oil fields with a significant differentiation and technical specifications of the reservoir fluids. The specific features of the development of the upper productive reservoir by a rod pump in this dual completion scheme are associated with low reservoir productivity due to the low mobility of the reservoir oil under natural temperature and pressure conditions. Aims and Objectives To research the possibility of natural heating of the upper productive layer due to the thermal energy of the lower layer and the heat produced by the rod and electric centrifugal pumps. Results A mathematical model has been developed for calculating the temperature field of the «well - productive formations - rod pump - electrical centrifugal pump» system taking into account the mechanisms of convective heat transfer, thermal conductivity, thermodynamic effects, and heat generation in the electrocentrifugal and rod pumps. A method for calculating the temperature of the fluid at the wellhead has been developed. By numerical solution of the heat conduction equation, a detailed study of heat distribution process in the upper productive formation interval was carried out. It is shown that due to the relatively small thermal conductivity of the fluid in the annular space of the well there is a significant temperature gradient, causing a decrease in temperature in the radial direction. To improve the heating of the upper productive formation efficiency with heated fluid in tubing, an improved design of dual completion unit using a heat exchanger to increase the heat transfer rate in the well has been proposed. The efficiency of the implementation of the periodic pumping mode by a rod pump using the proposed dual completion unit is shown.