Pilot Trial of New ES-HR-PCP Technology for Heavy Oil Reservoir
Abstract Kuwait Oil Company (KOC) has a vast pool of heavy oil reservoirs. Cost-effective artificial lift technologies, are required to produce these reservoirs, optimally. With this strategic objective, pilot of newly developed ‘ES-HR-PCP’ (Electrical Submersible Hydraulically Regulated PCP) technology, is carried out in KOC. Scope of this technical paper is to highlight significance of this technology and to share results of our pilot studies, which are carried out to maximize cold heavy oil production. With regard to our methodology, initially, techno-economic evaluation of ‘ES-HR-PCP’ system, is carried out. Selected well for the pilot, is having horizontal completion, with 3-1/2″ tubing and 7″ casing. Perforation is at 1900 feet MD (TVD at 686 feet). Oil API gravity is 17. Target liquid production rate is 200 b/d. After finalization of design, pilot of ‘ES-HR-PCP’ system is commissioned and pump performance is monitored for 6 months. Results are analyzed to determine success of the pilot. This study is based on actual field implementation and does not include lab studies. Technology evaluation has shown that ‘ES-HR-PCP’ system has definite edge over conventional PCP system. Standard PCP can handle only 25% of free gas; while ‘ES-HR-PCP’ can handle 90% of free gas, due to its unique design concept. ‘ES-HR-PCP’ system uses electric cable (and not sucker rods) and down- hole permanent magnet motor (PMM), to transmit power. PMM system can deliver more production, at higher speed; while expending less power. All these factors enable ‘ES-HR-PCP’, to be installed, near to the perforation zone, especially, in horizontal wells, thereby, allowing to attain lowest possible pump intake pressure and maximize production. During the pilot, peak liquid rate of 270 b/d (at 220 rpm), is achieved with installed ‘ES-HR-PCP’ system. Simulation studies also indicated that this technology could handle more than 40% of free gas, for given operating conditions. It is relevant to note that peak liquid rate of 223 b/d (at 375 rpm), is achieved, when this particular well, was installed with standard PCP, earlier. Substantial savings in power consumption is also witnessed by using ‘ES-HR-PCP’ system. Overall, performance of ‘ES-HR-PCP’ system, is observed highly encouraging during the pilot period. It is inferred from our studies that ‘ES-HR-PCP’ technology can offer distinct advantages over standard PCP, to accomplish, enhanced oil gain, operational flexibility and savings in operating expenses. Findings of this study can serve, as a valuable reference, for effective exploitation of heavy oil reservoirs of similar nature.