Selection Criteria for Artificial Lift System Based on the Mechanical Limits: Case Study of Golfo San Jorge Basin

Abstract

Abstract The Golfo San Jorge basin is the oldest productive basin of Argentina, and is located in south Patagonia. With 12,630 active oil wells, the basin produces 269,937 bpd of oil, and 2.9 MM bdp of water. The artificial lift systems are distributed as follows: 9,648 Sucker Rod Pumps (SRP), 1,615 Progressing Cavity Pumps (PCP) and 1,336 Electric Submersible Pumps (ESP). There are some important experiences with gas lift, plunger lift and hydraulic jet pump, but are not considered in this study. Close than 90% of the pumps are installed between 3,000 ft to 8,000 ft depth, producing flow rates over 1,500 bpd of fluid More than 3.1 MMbpd of water are injected in 2,400 wells in water flooding projects, therefore 41% of the oil is produced from this method. Due to the mature state of the basin, every year, new waterflooding projects are implemented for increasing and to hold the oil production of the basin. With every new project, not only increases the gross production per well, but also increases the depth of the new reservoirs. The combination of these factors resulted in a higher power to be transmitted from the prime mover to the pump, coupled with the increasing down hole temperature. Another factor, is the restriction provided by the most common casing diameter (5 ½ "), limiting the outside diameter of the pumps, the tubings and sucker rod sizes, and the shaft diameter too in some systems. In order to overcome these conditions, not only requires new technology in materials and design, but criteria for operation on the surface to achieve it. This paper presents a theoretical and practical analysis of the mechanical and operational limit of the most used artificial lift systems in Golfo San Jorge Basin such as the PCP, ESP and SRP. The analysis not only considers the technical aspects of each critical component and new technologies, but also is supported by reservoir information, operational conditions from 11,000 wells and software simulations for each system. One of the main objectives of this paper is to provide a guide for selecting and designing artificial lift Systems as SRP, PCP and ESP in similar oilfields and conditions.