Patent ID: 8485797
Filing Date: 2013-07-16
Classification: E21B,F04D

Abstract:
1. A method for boosting pressure of well fluid flowing from a subsea well, surprising: mounting a motor and a pump within a subsea capsule, the motor being filled with a dielectric lubricant, deploying the capsule in a subsea location, and isolating an interior of the capsule from a hydrostaic pressure of sea water in the subsea location; providing a submerged expansion housing external of the capsule in the vicinity of a sea floor, the expansion housing having a movable barrier therein, defining a primary and a secondary chamber; flowing well fluid into the interior of the capsule around the motor and into an intake of the pump and operating the motor and the pump to pump the well fluid from the capsule; communicating a dielectric lubricant pressure of the dielectric lubricant in the motor to the primary chamber within the expansion housing; communicating an intake well fluid pressure of the well fluid within the capsule before entering the intake with the secondary chamber within the expansion housing; and allowing the movable barrier to move to equalize the dielectric lubricant pressure with the well fluid intake pressure.