| 摘要 |
<p>A subsea wellhead assembly includes a production casing hanger defining a series of passageways from an annulus between a production casing string and an outer casing to a region that can communicate, for example, by way of an isolation sleeve, with a production tree. The passageways extend to the interior of the casing hanger. A positionally adjustable sleeve fits within the casing hanger and carries exterior seals that are disposed so that for a first position of the adjustable sleeve within the casing hanger, fluid passage through the series of passageways is blocked, and for a second position of the sleeve within the casing hanger, the fluid passage is allowed. The adjustable sleeve can be operated by a simple tool through the production tree.</p> |
