Abstract: A method includes deploying a tubing having a tubing bore in a casing in a wellbore, the tubing including a cup packer forming an annular barrier across a tubing-casing annulus separating the tubing-casing annulus into an upper annulus and a lower annulus, the cup packer having a fluid conduit extending substantially parallel to the tubing bore, and a barrier valve coupled with the fluid conduit to permit one-way fluid flow from the upper annulus to the lower annulus, communicating a fluid from the upper annulus through the barrier valve to the lower annulus, and closing the barrier valve in response to pressure in the upper annulus being less than pressure in the lower annulus.

Abstract: A turbocharger which by the configuration of a center housing portion thereof reduces heat transfer from a turbine housing portion to a turbine-end bearing in order to reduce oil coking in the latter. A phase-change material is included in the center housing portion. Control of lubricant flow further aids in reduction of oil coking in the turbocharger.