| 摘要 |
A subsea well assembly has features that allow a riser string leading to the surface to be purged of well fluids prior to pulling the riser string. The well assembly includes a riser connector that seats on a Christmas tree. The Christmas tree and connector have coaxial bores, the ends of which are separated from each by a chamber. A stinger interconnects the bores and extends through the chamber. The stinger has upper and lower pressure shoulders. Hydraulic fluid pressure applied to the lower shoulder causes the stinger to retract from the Christmas tree bore. This allows communication of the connector bore with an annulus passage also located in the connector bore. Fluid can then be pumped down the annulus passage to flow through the chamber and return up the connector bore, purging the riser of well fluid.
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