| 摘要 |
A wellhead seal assembly has a primary seal 116 and a secondary seal 144, each seal forming a metal-to-metal seal between inner 104 and outer 100 wellhead members. The primary metal seal ring 116 has inner and outer walls separated by a slot 126. A secondary metal seal 144 is located below the seal ring and has a bottom portion that contacts an upward facing shoulder of a hanger 108. A primary energizing ring 174 exerts downward force on the primary seal, causing a secondary energizing ring 128, located below the primary energizing ring, to energize the secondary seal 144. Once the secondary seal is energized, thus stopping downward movement of the primary seal and secondary energizing ring, the primary energizing ring energizes the primary seal. The taper of the primary energizing ring is varied to achieve a delay in the entry of the energizing ring into the slot 126 of the seal ring 116. |
