Design And Verification Testing Of New Balance Piston For High Boost Multiphase Pumps

Abstract

In 2011, the first Subsea Multiphase Pump (MPP) able to deliver a differential pressure of 2175 psi (150 bar) was introduced to the market. This major innovation for the subsea industry conquered the 17 year old 725 psi (50 bar) delta pressure barrier for existing multiphase pump technology. This achievement was made possible by the successful development of the first subsea MPP equipped with a balance piston, a technology which allows compensation of the axial thrust generated by the impellers, thus opening the way to pumps with high pressure differentials. This paper presents the background for the design of a balance piston that is required to function with a mixture of gas, water, viscous crude oil and sand, and also the rotordynamic issues related to pumping this type of raw process fluid. The paper also addresses the test set-up as well as the results from the verification testing of the rotordynamic behavior with a full scale 2400 BHP (1.8 MW) high boost multiphase pump.