Upstream Pumping Technology In Centrifugal Pump Mechanical Sealing Applications—Field Experience With High Duty Seawater Injection Pumps

Abstract

Among the technologies developed for oil and gas production centrifugal pump sealing applications, active lift technology is one of the most promising. The reliability of any centrifugal pump in a critical application is strongly influenced by the performance of the mechanical seals. It is widely accepted based on extensive operating experience that mechanical seals are the most vulnerable components in the pump structure and their life is not easy to predict. Depending on the product being sealed and operating conditions, seals can last from a few weeks to 20 years. Active lift, also known as “upstream pumping,” seals represent a new approach to the liquid sealing technology with the potential to offer a step change in seal reliability and resulting production gains. Developed from dry gas seal technology its major advantage over conventional contacting mechanical seals is that the face separation is stabilized and there is no rubbing between the seal faces. As rubbing is completely eliminated face deterioration is eliminated and face life is significantly extended together with a considerable reduction in the generated by the seal faces. Another important advantage of this new concept compared to traditional pressurized double seals is the elimination of a sophisticated pressurized barrier fluid system in favor of a much more simple system. It is obvious these days that “upstream pumping” sealing technology for higher pressure pumping applications is moving from small laboratory scale trials to wide industrial application. This paper takes the form of a general review of the product development and field experience accumulated during 18 months of operation with upstream pumping seals in a critical sea water injection pump application.