Heavy Oil Production With Steam Injection Using ESPs

Abstract

Abstract Heavy oil production using steam injection has become a common method of extracting oil. It is considered an enhanced oil recovery (EOR) method and is one of the extraction methods used in thermal stimulation of oil reservoirs. Steam injection is widely used in the San Joaquin Valley of California (USA), the oil sands of northern Alberta (Canada) and Venezuela. Steam assisted gravity drainage (SAGD) has become one of the more cost effective methods of producing fluid from oil sand reservoirs. This same technology is being applied to heavy oil reservoirs where viscosity is an issue. Wells involving steam injection operate at bottom hole temperatures (BHT) of 180°C to 250°C This is true when electrical submersible pumping systems (ESPs) are used, however when gas lift or rod lift are employed the BHT can exceed 320°C. This market requirement pushed the vendors to develop ESPs capable of operating continuously at these temperatures for reasonably acceptable run times (2 yrs +). The equipment specifications for materials and designs for this type of application involve the use of many high tech metals and elastomers designed for extreme temperature operation and temperature cycling. Steam assisted recovery projects challenge the ESPs with elevated temperatures, temperature cycling, H2S corrosion, abrasives, steam, and free gas. Development of steam injection projects parallel the similar requirements for equipment development used to run in harsh environments (high H2S), H2S-resistant materials can be used in varying configurations depending on the H2S quantity and the BHT. High-strength shafting and corrosion-resistant couplings, fasteners, and housings offer the most protection from corrosive elements. Cable and motor lead extensions (MLE) benefit from the application of lead barrier protection. Major developments in the insulating materials required for the stator, cable and motor lead extension enabled operators to increase the reliability of the ESP even when exposed to high temperatures and corrosive environments. The Centrilift CENtigrade™ elevated temperature production systems family is able to operate successfully in the harshest conditions. This product family consists of the Centrilift High Temperature™ ESP system, Centrilift Extreme Temperature™ ESP system, and Centrilift Ultra Temperature™ ESP system. Baker Hughes has a proven record of success with this equipment (Fort McMurray oil sands in Alberta, Canada), making it the first company to deploy ESPs capable of operating reliably at bottom hole temperatures as high as 250°C. The Baker Hughes Centrilift™ artificial lift product line offers ESPs, progressing cavity pumping systems (PCPs), gas lift, and surface pumps. This paper will focus on the development, capabilities and the successful implementation of the CENtigrade production systems.