Locating and cleaning up orphaned and abandoned wells is a major concern and the U.S. government is putting billions of dollars into these efforts.
An estimated 3 million of the wells exist in the United States, many of them leaking greenhouse gases and dangerous chemicals, posing environmental and public health risks, according to Sina Saneiyan, a geophysicist at the University of Oklahoma.
Abandoned wells are unplugged wells (primarily oil or gas wells) that have not been operated and maintained in accordance with prevailing statutes and regulations. Many abandoned wells have fallen into advanced states of disrepair. Orphaned wells are a subset of abandoned wells for which no owner can be determined.
“Although about 130,000 of these wells have been identified, a large portion of them have either missing or incomplete documents making them difficult to locate and plug,” Saneiyan said. Many are buried under several feet of earth and/or overgrown by dense vegetation. “The goal is to find these wells as quickly and as easily as possible.”
A Convenient Solution
Saneiyan said a fellow geoscientist, OU professor Kurt Marfurt, gave him that challenge shortly after he arrived at OU.
He found that most of the oil and gas wells use one form of iron alloy casings. He hit on a plan to use the magnetometer in most newer cell phones to locate the metal that has become magnetized in the Earth. The magnetometer is part of the cell phone navigation or GPS system.
“We utilize this magnetometer for the purpose of locating abandoned wells that have an iron alloy casing (cast iron, steel, stainless steel, etc.). Because the magnetic signal from these wells is usually really high, little to no data processing is required. Most of the times just plotting the data and contouring the collected points would suffice to locate a well,” he said. “The anomalies exactly appear in the form of clear red smudges on Google satellite map.
“So far, my team has been able to show that the land surveys (walking with a cellphone on a predefined grid) can easily detect well anomalies even is the well is buried under five feet of dirt. Based on this finding we designed a simple unmanned aerial vehicle survey setup where an iPhone 12 mini was put inside a custom-made sleeve and hung from a DJI Phantom 4 drone at about 1.5 meters below the drone.
“We surveyed two sites (one with an exposed wellhead and one without any visible signs at the surface) by flying the drone at three different altitudes – 10, 15 and 20 meters above ground level. Our results show that at an altitude of 10 meters above ground level the iPhone 12 mini magnetometer could pick the magnetic anomaly of either of the wells at intensities greater than or equal to 52 microteslas (Oklahoma’s background magnetic signal is about 50 microteslas); sufficient to accurately locate the wells. At altitude of 15 meters above ground level, the iPhone 12 mini was able to locate the wells but within about a 5-mile radius of the actual wells’ location, and it was unable to detect any magnetic anomalies at 20 meters above ground level.”
Testing the Method
Rebecca Theodorakis works for the Bureau of Land Management. In addition to being part of the government’s efforts to locate orphaned wells, she had two legacy wells on her ranch in McClain County in western Oklahoma.
Companies had tried several times over the years to revive of the abandoned wells with no success. Saneiyan used her wells as part of the testing of his new survey techniques to locate the hidden and buried metal structures and pipe.
She was contacted by H2OK, a company in Austin, Texas that offered to remediate one of the legacy wells in exchange for the underground pipe. The company salvaged about 12,000 feet of pipe and sold it for $6 a foot, totaling $72,000. Minus the $50,000 cost of the remediation, the company netted $22,000.
Theodorakis said the inexpensive drone survey method could be especially helpful because most of the money coming from the government is allocated for cleanup, not locating.
She cited the U.S. Fish and Wildlife Deep Fork Wildlife Refuge near the communities of Okmulgee and Henryetta in eastern Oklahoma.
The area was at the heart of the Oklahoma oil boom of 1918-20, but the wells were mostly exhausted by the 1930s.
The refuge was created in 1992 to protect and preserve bottomland hardwood forest and wetland habitats for the benefit of waterfowl, other migratory birds, fish and wildlife species native to the area. It currently encompasses more than 10,000 acres and will contain more than 18,000 acres once land acquisition is complete.
Theodorakis said the refuge is thought to contain more than 600 problem wells. She said the agencies involved have nowhere near enough staff to survey the heavily forested wetlands on foot, making the drone-phone surveys an affordable and efficient alternative.
She said the BLM uses drones in many ways, especially in the western portion of the United States, such as monitoring wild horses, land usage and keeping track of remote, largely inaccessible areas.
The magnetometer technology opens up other private and commercial uses such as locating underground tanks or other buried structures, she said.
“This UAV setup costs about $2,000 and is simple to operate,” Saneiyan said. “Minimal data processing is required to create the magnetic maps showing where orphan wells are located in any survey areas.”
“Both make this setup accessible to a broad range of users who are looking for ways to locate orphaned wells fast and easily. I would say this setup can be utilized by anyone who is concerned about the existence of such a well on their property. A simple, quick and cost-effective survey can help in most cases to find out if any orphan wells are at any sites! Given that the estimated number of orphaned oil and gas wells in the U.S. exceeds well into the millions, locating these well is very important to reduce the risks associated with them. We show that locating these wells can be relatively easy and accessible to anyone with minimal geophysical knowledge; all that is required is a smartphone (and a small drone). This ultimately results in better accessibility of the technology to the general public,” he said.
Applications for ‘Citizen Scientists’
The low costs of such a setup makes it an area potentially ripe to attract “citizen scientists” – members of the general public who wish to take part in scientific research.
“I have been in contact with Lindsay Wancour of Adventure Scientists. They are working with the Clean Air Council and Pennsylvania Department of Environmental Protection in an effort to find orphaned wells in Pennsylvania and measure their emissions. Adventure Scientists’ team of citizen scientists would be able to use cell phone magnetometers to help locate wells, particularly those that may have been buried. The idea is that the ‘citizen scientist’ volunteers can scan an area with their cellphones or just turn on the magnetometer while going on a hike and then look at the data and see if any high magnetic anomalies are observed. Then a team can go an investigate the region that an anomaly was detected to see if a well exists or not,” Saneiyan said.
Saneiyan earned his bachelor’s in mining engineering from the University of Tehran in Iran, then a master’s in petroleum engineering in 2014 from Sharood University of Technology, Iran, and a doctorate in environmental sciences from Rutgers University.
He said his research mainly focuses on the geophysical characterization of near-surface processes through a wide range of methods such as electrical resistivity, induced polarization and electromagnetics.