By Ion Simonides, Max Harleman, Akash Hegde, Jeremy G. Weber, and Kristin M. Carter
In June 2012, East Resources, a Royal Dutch Shell subsidiary, was drilling a Marcellus shale gas well in Tioga County, Pennsylvania. During development of the area, methane began to bubble out of nearby streams, the water well of a neighboring cabin overflowed, and a 30-foot geyser of water and natural gas erupted out of a nearby abandoned well. The abandoned gas well had been drilled in 1932, and while Shell knew of its proximity to their operation, it thought that it had been properly plugged. Apart from incidents related to new drilling, abandoned wells, especially those that have not been properly plugged with cement, can leak brine and oil that can contaminate soil and water, as well as methane, a potent greenhouse gas that contributes to climate change. Abandoned wells can also provide a pathway for methane to accumulate beneath nearby homes, which has caused several nonfatal home explosions in Pennsylvania, and a widely publicized fatal explosion in Firestone, Colorado.
Old oil and gas wells abound in Pennsylvania, but it is unclear how many are known and of these, how many are likely abandoned. The state has experienced drilling for more than a century and a half, but modern record keeping only began when the Gas Operations, Well Drilling, Petroleum and Coal Mining Act of 1955 established permitting and registration requirements for new wells. The Department of Environmental Protection (DEP) acknowledges that it does not know the number of wells drilled prior to 1955, and that hundreds of thousands of wells remain undocumented. But what wells does the state know about and how many are likely abandoned?
To this end, we combined three datasets in which the state maintains oil and gas well records: the DEP’s online repository of production reports, the DEP’s online well database of permitted wells, and the Department of Conservation and Natural Resources’ (DCNR) Exploration and Development Well Information Network (EDWIN). EDWIN contains information on permitted wells, as well as more than 10,000 wells that were never officially permitted but have adequate records and location information, thanks to DCNR’s ongoing efforts to locate, validate, and digitize this information. The steps that we took to combine the three datasets can be found in this online appendix.
Our analysis of state records shows 180,788 unique conventional wells (see figure). All three datasets contain a variable about the “status” of a well, which indicates that 47,992 of these wells have been plugged. The state has no record of plugging for the remaining 132,796 wells, and we therefore classify them as unplugged.
Conventional Oil and Gas Wells in Pennsylvania State Records
Note: Calculations based on data from DEP production reports, DEP's well database, and DCNR EDWIN. Percentages are rounded to the nearest integer.
Of the unplugged wells, 38,712 did not appear in any production reports submitted between 1980 and 2017. Thus, 21 percent of all wells in the state records have not reported production in at least 37 years. Many of the wells were drilled prior to 1955 before the state began permitting wells and keeping record of who was responsible for them. But others were drilled after 1955, and their operators have not complied with updated state laws, which require them to report production annually. If no production is reported, there is no proof that the well is not “abandoned” as defined in Pennsylvania law. When a well is classified as abandoned, the operator must plug it, remove all drilling and production equipment, and restore land, water, and vegetation to pre-drilling conditions.
Our estimate of potentially abandoned wells in state records is conservative because it only includes wells that never reported production in the last 37 years. Many more unplugged wells in the state’s records have reported at some point since 1980, but not in the past 12 months, which could earn them the “abandoned” status based on state law. It is unclear how many of these are currently being used to produce oil or gas, and how many are effectively abandoned.
The 38,712 number is a useful starting point and helps put in perspective current state policy for addressing abandoned wells. The DEP administers a program to plug wells that do not have a responsible party. Plugging activities are prioritized based on wells that pose the most risk to health or the environment and the agency has plugged about 3,000 wells since the program began in 1989. The total number of wells currently on its list of orphaned and abandoned wells is 8,739, less than one quarter of the number of known wells that are likely abandoned. It cost the state $13,000 to plug the typical well over the period 2005 to 2013. If the 38,712 likely abandoned wells are similar, plugging them would cost upwards of $500 million. If an operator with resources to plug the wells cannot be identified, the cost would fall upon the state. To put the cost in perspective, the state spent $18.6 million dollars plugging wells between 2005 and 2013.
Ion Simonides is a Master of International Development student at the University of Pittsburgh, Graduate School of Public and International Affairs. His research centers on abandoned oil and gas wells and the economic and environmental issues they present.
Max Harleman is a PhD student at the University of Pittsburgh, Graduate School of Public and International Affairs. His research focuses on the governance of energy projects and their associated economic and environmental impacts on communities near development.
Akash Hegde is a Master of Petroleum Engineering student at the University of Pittsburgh, Swanson School of Engineering.
Jeremy G. Weber is an Associate Professor at the University of Pittsburgh, Graduate School of Public and International Affairs and the Department of Economics. His research cuts across energy, agriculture, the environment, and well-being. He teaches classes in quantitative methods and energy and environmental policy.
Kristin M. Carter is the Assistant State Geologist of the Department of Conservation and Natural Resources Bureau of Topographic & Geologic Survey and Director of the Economic Geology Division.
About the blog: The GSPIA Energy and Environment blog provides commentary and analysis that furthers understanding of E&E issues of public interest. Its primary contributors are GSPIA faculty and students.