Subsea Wellhead Components - Part 2

Metal to Metal Annulus Seal Assembly

The metal-to-metal annulus seal assembly is used to seal off the casing string annulus pressure from the bore pressure to isolate geological formations from one another. The metal-to-metal assembly usually need practice testing to confirm that it can withstand the high pressure and temperature.

Elastomeric Annulus Seal Assembly

The elastomer seal assembly is used in an emergency when the primary seal fails to function should the bore of the wellhead or casing hanger have a deep scratch. The elastomer seal assembly seals in a different vertical location in the wellhead, which hopefully seals away from the damaged area.

Casing Hanger Running Tools

The intermediate and production casing hanger running tools run the casing hangers and set the annulus. These tools normally are designed using the same technology, lessons learned, and in many cases the same parts as the standard 15 ksi running tool.

BOP Test Tool

The BOP test tool is designed with similar approach as the other components and tools in this system. It is used to test the BOP to the future formation pressure that the operator is currently drilling into and is also used to run and retrieve wear bushings.

Isolation Test Tool

The isolation test tool is used to test the pack-off per MMS requirements while simultaneously isolating the BOP stack/riser. The tool operates with a simple straight-in/straight-out approach. Once set in position with weight down, drill string pressure is applied to the target test pressure up to 20 ksi.

OD Wear Bushing and OD BOP Test Tool

The 13-5/8" OD wear bushing and 13-5/8" OD BOP test too are key tools to expediting completions while the 18-3/4"-20 ksi BOP is being developed for the industry. This wear bushing and running tool combination is run through a 13-5/8"-20 ksi BOP that latches either to the wellhead or to the 20-ksi tubing head, and they allow for BOP tests. The wear bushing protects all seal surfaces, including those on the production casing hanger while drilling/logging operations are being performed.