A casing hanger is a component of a wellhead that tops a natural gas or oil deposit. It supports and braces the casing used to protect formations around the well as technicians drill and prepare to extract resources. Standardized sizing is used in the industry for casing and accompanying hangers, which come in several designs from manufacturers. For specific projects, custom versions may be available, although a custom casing hanger can be costly because of the need for specially machined components and similar features.
The device sits in the wellhead below the production tubing and above the casing itself. As technicians drill, they lower casing into the well to seal it and lock it in place with a casing hanger, dropping a smaller drill through the casing to reach lower depths as needed. Casing hangers need to be able to support substantial weights not just of tubing itself, but also of the loads it may carry. They are designed to handle extreme weight and pressure without failing.
Depending on design, a casing hanger may automatically or manually seal as it grips the casing and interlocks with other components of the wellhead. Technicians select the appropriate size given the specifications of the existing components and the casing they plan to use, carefully checking all parts to make sure they are properly installed before moving to the next section of the well. This process includes documentation for safety reasons so people can demonstrate the steps taken to secure the wellhead.
Casing hangers and other components of the wellhead may be sealed inside protective tubing and wrapping to reduce the risk of problems. They can be accessed through hatch points, and continuous monitoring of conditions inside the wellhead is available with remote sensors to provide feedback on pressure, temperature, and other characteristics. Technicians may monitor these onside as well as at a remote location so companies can remain continuously aware of situations at their wells around the world.
Equipment like a casing hanger may last 20 years or more when it is properly maintained. Casing hangers need to be regularly inspected along with other components for signs of strain like cracks and fatigue. Wells also require periodic cleaning and overhauls to confirm that all their systems are in working order. This maintenance ensures that problems are caught early, providing an opportunity to shut production down and replace worn well parts before they fail catastrophically.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.