Frequently Asked Questions

It depends.

Inactive wells do affect land use and value, but they may or may not be actively causing other problems. The threats to wells vary a good deal, and so does the ability of wells to withstand those threats. In all cases, however, the risk of failure increases over time. 

Most wells have “mechanical integrity,” meaning that the reservoir fluids are physically constrained to the inside of the well’s metal casing and equipment. However, the metal and cement used to create that integrity can both decay. 

Some clues are obvious, but more consequential failures cannot be identified by observing the surface.

Leaks from the equipment into the air or onto the surface are obvious, and gas migrating through the soil to the surface can sometimes be identified as distressed, dead or absent vegetation. But fluid flows below the surface are not visible at the surface. 

Higher risk of failure or consequences of failure are created by elevated pressure or fluid levels inside the wellbore, which can be measured simply from the surface by those with the right and the training to do it safely. But the movement of gases and fluids below the surface–particularly through or into fresh water zones–cannot be determined from surface observations. 

Some risk factors are known, but well failures remain unpredictable.

The stresses and threats of failure vary widely across areas based on things like the humidity of the air, the corrosivity of the oil and groundwater, the nature of zones drilled through, the nature of fluids produced, and operations conducted on the wells. [See Research for more information] 

The quality of well design and construction affects how resistant wells are to these stresses. The resistance to failure tends to correlate to the oil companies responsible for drilling the wells and the service companies they hired to do the work. 

The risk of failure increases with time as stress and deterioration accumulate.

Yes, but not often. 

Subsurface liquids on the ground can change the nature of the soil and can percolate down through the soil into fresh groundwater. Such spills of oil and formation brine generally occur from actively producing wells or leaking storage tanks because most idle wells do not have enough pressure remaining in the formation to bring the formation liquids to the surface (only gases). 

However, nearby injection of waste water increases the pressure of fluids in the geologic formations, and this increase in pressure can be enough to lift fluids to the surface. Occasionally, high-pressure formations do create dramatic failures visible at the surface such as geysers and sinkholes.

Yes.

Natural gas escapes more readily than oil or salt water. Depleted formations often hold enough pressure to push gas to the surface wherever a path exists, usually the wellhead or surface equipment.

The main component of natural gas is methane, which is invisible and has no odor. Methane is also a powerful greenhouse gas, responsible for roughly 30% of global warming to date.

Natural gas often carries other compounds that are hazard in very small amounts. Hydrogen sulfide (H2S) is toxic at low concentrations. It smells like rotten eggs at first, but it deadens the sense of smell as concentrations increase, so odor is not a reliable warning. Benzene and other volatile organic compounds are carcinogens and are more likely to be present when you can smell crude oil.

Detection requires specialized equipment and handheld gas detectors are widely available and can be inexpensive.

Yes, but the frequency is not clear. Improperly maintained or degraded wells that are unplugged can pollute groundwater resources by forming a pathway for contaminants from the subsurface. 

Protection of groundwater has been for decades a primary justification for plugging wells. And despite the difficulties of proving a cause for contamination, there are documented instances of groundwater pollution from unplugged wells. The bigger question is the unquantifiable risk. 

Groundwater quality is not universally tested, so it is not always identified. When contamination is found, the cause can be very difficult to interpret, and often the cause is never determined. Only a small volume of contaminants is enough to render large volumes of water unusable for human purposes, and remediation is often impractical. So without protections, problems may become large and irreversible before they are found. We believe that the best policy is prevention. 

Most properly plugged wells perform as intended, but there are no guarantees. Some wells experience failures years or decades after they are plugged. Unfortunately, the failure rate and causes are not well understood.

The risk of failure depends on many factors, including the age of the well, how long it sat inactive before plugging, the quality of the original well construction, and the quality of the plugging work. For landowners, the greatest concerns are often surface releases of fluids or gas, damage to agricultural operations, and uncertainty about future liabilities associated with older wells.

Warning signs include damaged equipment, leaking fluids or gas, bubbling water, nuisance odors, and distressed or dead vegetation. 

However, leaks of poisonous hydrogen sulfide cannot be seen, and they cannot be smelled at dangerous concentrations. Equipment may contain fluids, and–particularly at the wellhead–those fluids might be pressurized. We strongly encourage you not to approach wells which might be dangerous and not to touch any equipment on any wellsite.

If you suspect a  problem, you can contact the oil company directly. Its name and contact information should be posted on a nearby sign that also includes the well’s name. For immediate injury or fire, always call 911.

You can also contact the RRC with concerns about spills and leaks, and the Texas Commission on Environmental Quality with concerns about air emissions and odors. And you don’t have to be the landowner to report your concerns. Anyone who suspects a well is leaking or unsafe may contact the regulatory agency in the interest of protecting public health and the environment.

You can refer to this guide for more information on how to file a complaint with the Railroad Commission.

The request needs to be made to the responsible party. For most wells, you need to contact the name of the oil and gas company listed on the sign for the well. For orphan wells, you need to contact the RRC’s program for orphan wells, the State Managed Plugging Program.