How Long Does a Well Last?
It’s important to know about the life expectancy of a well since the cost of decommissioning an oil or gas well is high. In addition, the lifecycle of a well varies depending on the type of well, its location, and how it’s managed.
Below, we look at the lifespan of oil and gas wells. We also describe different types of wells based on their age and activeness.
What Is the Average Lifespan Of an Oil Well?
On average, a well can last between 20 and 30 years. Some wells may not need to be abandoned until they’ve been producing for up to 50 years, while others are abandoned as soon as they cease to be profitable.
In fact, a well in Pennsylvania has been operating continually for the past 150 years. It produces anywhere from seven to 10 oil barrels in a day.
What Is the Average Lifespan Of a Gas Well?
The average lifespan of a gas wall is around 10 to 15 years. However, it may differ based on the type of gas well and its location. For example, if a gas well is located in an area with higher reservoir pressure, it may last longer than usual.
For instance, Colorado is home to over 53,000 active gas and oil wells. The average lifespan of a well is 12 years in the area. But even in the region, the lifespan differs from one place to another.
For instance, it’s around eight years in the Piceance Basin, whereas wells in Weld County stay active for about 11 years. So, it comes down to the production rate and other factors.
Well Classifications: Types Of Wells Based On Age and Activity
Oil and gas wells are divided into several categories based on their activeness status. Here’s the classification.
A well is active when it is producing oil and gas. That means the well has been drilled, completed, tested, and is currently operational.
Active wells are further classified into two categories:
New Active Wells
These are wells that were recently drilled and completed. They began producing within the last few years.
Mature Active Wells
These wells have been producing for a longer period. Most of them have been in production for at least five years.
An inactive well has been drilled and completed but is not producing oil or gas. It can still be used in the future, but it is not producing anything at the moment.
A well is considered inactive if it has not produced any gas or oil in the past 12 months. In most cases, this is temporary. The well can be restarted or repaired to increase production.
Inactive wells often show declining production from an oil and gas field. They can also pose an environmental risk if they are not properly maintained. Therefore, it is important to monitor inactive wells for leaks or other problems that might cause contamination of the surrounding area.
A suspended oil well is a well that cannot produce oil or gas for an extended time. The most common causes are an inadequate flow rate, reservoir depletion, or structural problems.
Suspended wells are generally not considered economically viable and therefore remain inactive. Sometimes, a suspended well can be reactivated if the underlying causes are addressed. However, this requires a significant investment of time and capital, often not feasible in many cases.
A well is abandoned if it is permanently shut in, with no plans for further operations. Once a well is abandoned, the site is reclaimed and remediated.
Typically, there are state requirements for the abandonment of any well, and a licensed professional must be consulted before any work. Wells can be abandoned in various ways, including plugging, filling in the casing, or cutting off the wellhead.
State governments often regulate the process of plugging a well to ensure the well is sealed properly and permanently, regardless of the method chosen. Regulations also typically require that all abandoned wells be reported to local authorities.
An orphan well does not have an identifiable owner. A well may become an ‘orphan’ if the owner fails to comply with regulatory requirements and state or federal regulations require that it be plugged in.
Orphan wells are typically plugged and abandoned per state regulations, then reclaimed and remediated by the state or federal government. Reclamation and remediation typically involve restoring the land to its original condition and may include removing any hazardous materials used during the drilling process.
The Orphan Well Association is an example of a non-profit organization that works to plug and abandon orphan wells in a safe and cost-effective manner while protecting the environment.
What Happens After a Well ‘Dies’?
An oil or gas well dies when it can no longer produce output at a commercially viable rate. When this happens, the well is “shut in” or plugged and abandoned.
It means that the well is sealed off from the surrounding groundwater and geology. In 2021, the American Petroleum Institute created a standard for the remediation and closure of wells after they have lived their lives. The standard is designed to ensure environmental stewardship and safety.
In some cases, it may be possible to restore production later by re-entering the well and installing a new producing technology.
In other cases, the well is permanently plugged and abandoned. The company responsible for the well is obligated to follow strict regulations in plugging and abandoning a well. They have to:
- Remove the wellhead equipment
- Fill the well bore with cement
- Cap the well bore with a steel or concrete plug
- Clean up any land surface contamination that occurred during drilling and production activities
Finally, the authorities inspect the site to ensure the company has followed the regulations. The company must also perform landscaping if the area is close to residential space. The idea is to erase the traces of the well.