Metal-to-Metal Seals
The proprietary metal annulus seal is rated for 15,000- psi service. Gas testing has been successfully completed to 350°F, with the seal maintaining integrity even after cool-down. The metal-to-metal seal is weight set with the hydraulic action of the Single Trip Tool completing seal energizing and lockdown. When fully set, there are multiple metal-to-metal sealing areas in the housing and casing hanger. When lowering, the seal is firmly held in its retracted position to prevent premature energizing.
Elastomer Seals
The UWD-15 elastomer seal assembly provides a reliable alternative to metal-to-metal seals. It is rated to the same operating temperature and pressure and is fully interchangeable with the metal-to-metal seal assembly. The proprietary FMC Subsea Drilling Systems’ elastomer expands radially and is preloaded as setting pressure is applied. The elastomer seals are positioned above the metal-tometal sealing area. As the seal is energized, anti-extrusion rings situated above and below the elastomer are forced into contact with the sealing surfaces. During running, the elastomer seals are protected by the lower body of the packoff and the large clearances between the seals and the mating seal surfaces.
UWD-15 H-4 Profile
The UWD-15 wellhead family uses the H-4 profile with the a proprietary FX-2 secondary emergency seal preparation as standard in all systems. The system can accommodate both the standard H-4 and HD H-4 wellhead connectors as well as the SHD H-4 connector with a conversion kit installed. Additional connector profiles are available on request.
Drill Cutting Injection Wellhead System
The Drill Cutting Injection Wellhead System is designed for guideline water depths. In order to reach ultra-deepwater depths, the system will be adapted to accommodate a preloaded system and guidelineless operations. The system facilitates direct access into the 20" x 13-3/8" annulus, for reinjection of contaminated downhole cuttings. Communication into the 20" x 13-3/8" annulus is provided via the guidebase injection pipework, the guide-base center-ring, the 30" conductor housing and the 18-3/4" wellhead housing. Emergency isolation during drilling of the hole for the 13-3/8" casing is facilitated via an isolation sleeve. This design prevents a possible well abandonment situation in the event of leakage of the injection system seals. The system is rated for 3,000 psi injection working pressure. Cuttings are injected via a 2.06" line allowing for a maximum injection rate of 125 gpm of slurry mix or 250 gpm of seawater.
Annulus Monitoring
FMC Subsea Drilling Systems can provide UWD-15 drilling systems for annulus monitoring. For details, contact FMC Subsea Drilling Systems.