Abstract: A system that can include a centralizer configured to be radially positioned between a tool and an internal bore of a tubular, wherein the centralizer is configured to engage the internal bore and the tool via a plurality of biasing devices circumferentially spaced away from each other about a center axis of the centralizer. A method can include installing a biasing device in a plurality of protrusions that extend radially outward, extending a portion of each biasing device past an outer radial surface of a respective protrusion to engage a tubular, and extending a portion of each biasing device past an inner radial surface of a central bore of the centralizer to engage a tool, where the first portion and the second portion are configured to substantially align a center axis of the tool with a center axis of the tubular when the tool is installed in the tubular.

Abstract: Method and apparatus are provided to accelerate the cooling of thermally sensitive components in a chamber of a downhole instrument assembly. In accordance with the invention, a passage is formed in the chamber and a fluid is conveyed through the passage to cool the components to the desired temperature. By using the method and apparatus of the present invention the amount of time to cool the components is dramatically less than the time required for cooling using conventional techniques.