| 摘要 |
The invention relates to an insulation device for wells by controlled supply of the internal volume of an expandable sleeve placed on a casing, comprising a non-return valve placed in a passage which connects the internal volumes of the casing and of the sleeve and a three-way valve which switches a single time between an initial state in which a link connects the internal volumes of the casing and of the sleeve to expand the sleeve and a final state in which the link between the internal volumes of the casing and of the sleeve is interrupted, whereas a link is set up between the internal volume of the sleeve and an annular volume of the well, the three-way valve and the non-return valve forming, after switching, two non-return valves mounted in series and in opposite directions on the passage connecting the internal volumes of the casing and of the sleeve. |
