Hydraulic Concentric Tubular Pumping System for Lifting Oil in EOR Completions

Abstract

Abstract Conventional artificial lift systems are limited in their application by depth, borehole trajectory, and chemistry of the produced media. This paper presents a concentric tubular pumping system, combined with an efficient hydraulic pump to overcome the limitations of existing artificial lift systems and to assure a cost-effective production. This pumping system consists of a specially designed pump&piston combination which is driven by a hydraulic pressure unit from the surface without any mechanical connection. The hydraulic pump itself can be circulated into and out of the borehole or can be run by slickline, resulting in fast and low-cost operations. The pump is designed to be run as a concentric tubular pumping system, which causes several advantages, especially in gas, thermal or chemical injection EOR installations. This new pump type is designed and manufactured in cooperation with the industry and tested at the Montanuniversität Leoben, Austria. The performance and wear tests have demonstrated the saving potential in terms of energy efficiency as well as reduced CAPEX and OPEX. The unique design of this pump owns a very low number of moving parts, such no mechanical connection to the surface, and such providing minimal exposure to wear and corrosion. Tests have shown that the pump is very adaptable in terms of production rate, which just requires a change in surface hydraulic pressure. Based on experience the concentric tubular pumping system is the best selection for thermal and chemical EOR methods to enhance the lifetime of the completions. As a result of the natural phase separation of liquids and gases the presented pumping system has shown to be the ideal choice for the usage in all types of wells for gas injection EOR methods too. This completely new pump type exceeds the performance of existing artificial lift systems, increases the mean time between failures and reduces the lifting costs essentially. These major issues are most important in times of low oil price, especially for tertiary recovery methods.