Controlling the pressure within an annular volume of a wellbore

摘要

A process for controlling the pressure within a confined volume comprising: a) providing a volume containing a first fluid having a first pressure and a first temperature within the volume; 5 b) replacing at least a portion of the first fluid within the volume with a second fluid comprising at least one anhydrous inorganic material; c) sealing the volume to produce a confined volume; d) heating the fluid within the confined volume, such that the fluid is at a second pressure and at a second temperature; 10 wherein the second fluid is preselected such that the second pressure is lower than had the confined volume contained the first fluid only at the second temperature.