摘要 |
<p>The present invention is directed to systems and methods for initiating annular obstructions in wells used in, or in support of, enhanced oil recovery operations-particularly enhanced oil recovery (EOR) efforts involving steam injection (e.g., steam flooding). In at least some instances, system and method embodiments of the present invention utilize one or more passively-activated annular obstruction devices (and/or hybrid active/passive devices) for inducing annular obstruction, wherein the associated passive or hybrid activation is at least partially controlled by thermal means such that it can be deemed to be thermally-directed or thermally-controlled. Such thermally-directed passive activation can afford considerably more control over the annular obstruction process and, correspondingly, over the overall steam injection into the formation and associated reservoir-thereby providing more efficient recovery of hydrocarbons.</p> |