Casing Hangers

Casing hangers are devices that allow casing to be set in the well bore during the drilling phase of an oil or gas well. There are two basic designs of casing hanger, slip-type or mandrel. The slip-type is the conventional and most commonly used. The mandrel-type is normally used when special needs arise during the building of the well. Both allow for the Tens of Thousands of pounds in weight of the casing string weight to be transferred from the derrick of the drilling rig to the load shoulder in a casing head or spool. A Casing Hanger performs the following functions:

•  Suspends the casing load
•  Transfers casing weight
•  Centers casing
•  Provides a primary seal in the casing annulus
•  Creates an annular space
•  Allows for testing of connections

Slip Casing Hanger Components

C-21 Casing Hangers

C-21 casing hangers are the non-automatic solution for hanging casing. The split bowl utilizes the same upper slip segments as the C-22 and C-29 hangers and incorporates a separate seal assembly. This has two benefits. It prevents any well or test pressure from adding to the radial compression of the slip segments. And it is a primary casing seal that can be replaced during workover operations without picking up the pipe.

• Non Automatic casing hangers are typically used when the casing string weight is  not sufficient enough to energize the seal mechanism in automatic casing hangers
• The Type-H seal ring utilizes S (OD) and CS (ID) seals to provide the primary seal on the string of casing being suspended in the casing hanger
• The C-21 casing hanger seal mechanism cannot be used if LDS are present in the upper flange of the casing head

C-22 Casing Hangers

C-22 automatic casing hangers are designed for use with the venerable C-22 casing heads and are an industry standard around the world.

• The C-22 automatic casing hanger has an integral, compression-type sealmechanism that automatically actuates with the weight of the casing string
• The sealing element made into the casing hanger provides the Primary seal on the string of casing being suspended
• The C-22 casing hanger is hinged on one side and latches on the other
• The C-22 casing hanger is designed to be used with theC-22 casing head and is utilized for most intermediate casing string weights
• C-22 Casing Hangers can be utilized in a C-29 casing head or spool

C-29 Casing Hangers

Sentry C-29 casing hangers incorporate a set of 8 independent slip segments. Of these 4 are located above the packing element and 4 below the packing element. These hangers are best suited for extreme casing string weights.

• The C-29 casing hanger is designed to be used with the C-29 Casing head or spool
• The C-29 automatic casing hanger has an integral, compression-typeseal mechanism that automatically actuates with the weight of the casing string
• The sealing element made into the casing hanger provides the Primary seal on the string of casing being suspended
• The C-29 casing hanger incorporates many of the same features as the C-22 casing hanger, but is designed for much higher casing string weights

Mandrel Casing Hangers

Sentry Mandrel-type casing hangers are used when special needs arise during the building of the well. They can be customized to meet the needs of your well design in almost any design or configuration. Consult your Sentry Sales Representative to discover how we can help design one to fit your unique requirements.

• Mandrel casing hangers can be utilized in conjunction with a pack-off to minimize the time spent setting casing by allowing for the pipe to be set and the annulus sealed without removing the BOP’s
• A mandrel casing hanger can be used to secure the well for the safe installation of FRAC equipment by incorporating a back pressure valve profile in the ID
• The mandrel hanger can be utilized to simply prevent any hot work normally performed for the setting of slip-type casing hangers
• A mandrel casing hanger may be designed to meet all three needs mentioned above, in one casing hanger