What is a Wellhead?

Mary McMahon
Mary McMahon

A wellhead is the topmost point of a well. Wellheads serve a number of functions while a well is being drilled, once it is completed and operational, and when it is shut down, either temporarily or permanently. The wellhead is installed early on in the process so that it can serve as a point of attachment for a blowout preventer, a piece of equipment which prevents catastrophic failure of a well, and once a well is completed, equipment for regulating well operations can be attached at the wellhead.

Wellheads serve a number of functions while a well is being drilled.
Wellheads serve a number of functions while a well is being drilled.

The wellhead provides pressure sealing as well as room for casing and tubing related to the well, including permanent and temporary equipment introduced into the well. When a wellbore is completed, a pump can be attached to the wellhead or it may be fitted with a device known as a Christmas tree. The Christmas tree holds valves which are used to control pressure inside the wellbore and to regulate the flow of fluids from the well. This device can also be used as a point of entry to inject things into the well.

The term “Christmas tree” is a reference to the shape of this device, which does from a distance resemble a festively decorated tree because it is usually brightly colored for safety and highly branched to make room for valves and pipes. The wellhead is right at the surface and may be partially buried, while the Christmas tree projects so that it will be accessible to technicians who need to be able to adjust it in order to operate the well successfully.

Wellheads can vary in size and complexity depending on the type of well and the location. With things like undersea oil wells, for example, there are substantial pressure and pollution concerns which must be addressed to make the well as safe as possible. By contrast, with something like a household water well, there are fewer safety concerns and less need for very precise control.

Engineers who work with wells want to avoid situations in which wells fail or other problems develop. Control panels are usually located in central areas to provide remote access and the well can also be worked on at the wellhead. When wells need to be temporarily taken offline or maintained, adjustments can be made to the Christmas tree to address concerns about pressure differentials and other situations which could contribute to the development of workplace hazards.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


@geekish - My husband and I found the same problem with our well system when we bought the house, while our water pressure is still not going to knock our socks off we did find a little fix that helped, and may help you with the drinkability of your water.

The fix was so simple - we changed the filter.

Neither of us had well systems growing up so when we called a well person to come out and help us he showed us how to change the filter. He said it looked like it had not been changed in years.

We still have high sediment water so we still do not drink it; even with regular changes of the filter but it is *much* better than before.

There are many anecdotal suggestions that I have read about increasing water pressure with wells, but my husband and I have not taken that next step - too busy decorating right now!


I purchased my first house two years ago and one of the odd things about the house was that the wellhead was only a few from the house and the second thing was that the person who looked at the wellhead mentioned it looked older. He suggested replacing it.

This is my first ever on a well versus city water experience and I must say I can drink pretty much any tap water except ours! Will changing out the wellhead give us better tasting water or does it not have anything to do with that.

Also our pressure is not the greatest - again will changing the wellhead fix this or is there a specialized wellhead pump that is better at fixing this problem in particular?

Post your comments
Forgot password?