Sub-sea pumping system and an associated method including pressure compensating arrangement for cooling and lubricating fluid

摘要

A sub-sea pumping system for pumping an effluent from a deep-sea wellhead comprising a topside module, a sub-sea module, and an umbilical connection between the topside and sub-sea modules. The umbilical connection comprises a threephase electrical power line and an hydraulic fluid supply line to an electrical canned motor. The hydraulic fluid is a single medium fluid, is compatible with the effluent being pumped, and is circulated through the sub-sea module for cooling and for lubricating the seal and bearing arrangements of the motor and the pump. The hydraulic fluid is circulated through a submerged pressure compensator which includes a metal bellows assembly. The compensator is responsive to the pressure of the effluent being pumped and pressurizes the hydraulic fluid flowing through the motor and the pump for the cooling and the lubricating of their respective seal and bearing arrangements at a pressure above the pressure of the effluent being pumped.