It’s a problem as old as the industry itself. The initial oil rush in the late 1800s spread like wildfire through Pennsylvania, and by 1891 the state’s annual crude output had hit 31 million barrels, or 58% of the nation’s total oil production for that year. However, by the turn of the century the bloom was off the rose. Pennsylvania’s once-robust oil allure had been eclipsed by finds in Texas, California, and Oklahoma, each spawning its own regional oil booms. So why the history lesson? Because it’s important to understand the potential volume and impact of orphan wells in the US. In the infancy of the industry, plugging-and-abandonment (P&A) techniques were crude at best, if anyone even went to the trouble. Worse still was the overall record keeping at the time. With oil booms around the country setting off races to harness as much black gold as possible, wells were being drilled at breakneck pace. Once these earliest wells were tapped of their commercial usefulness, operators moved on to the next. There was little-to-no over-sight. No regulations. No standards. The result? Thousands, if not more, of scattered, undocumented wells. “Back in the day, you have people drilling wells, and nobody’s keeping track of where the wells are drilled and who owns the wells,” said Daniel Raimi, fellow with Resource for the Future, an independent institution that conducts environmental, energy, and natural resource research. “The government’s not keeping track and has little to no regulation in place to ensure that operators safely decommission their assets at the end of their lives. As a result, you have wells that maybe produce for a couple of years, and then the owners walk away. Multiply that by a couple of hundred thousand and now you’ve got a problem.” Today, there is plenty of oversight and regulation for the industry to leave abandoned wells in much better shape than those earliest probes. However, orphan wells are still a problem. To paint the clearest picture, it would be prudent to define what an orphan well is. This is where we run into our first problem. Definitions can vary wildly from state to state and organization to organization. Some lump all abandoned, unplugged wells into their counts as orphan wells. Others count all idle wells. However, for the sake of clarity we will define orphan wells as those nonproducing, idle wells whose ownership is unknown. By that definition it is safe to say that many of the nation’s earliest wells fit that criteria. In more modern times, orphans result from idle wells whose owner goes belly-up prior to any P&A work. In most of these cases, bonds are employed to help offset the cost of plugging these wells. However, while they vary state to state, most bonding minimums do not cover the full cost of abandonment and remediation, if needed. According to the US Environmental Protection Agency, there are about 2 million unplugged, abandoned oil and gas wells scattered across the US. Other experts place the number higher; some believe it is lower. Some researchers believe as many as half of those could be orphan wells. A survey by the Interstate Oil and Gas Compact Commission in 2018 put the range of orphaned and idle wells at around 560,000 to 1.1 million. Again, abandoned doesn’t always mean orphaned. One fact that can be extrapolated from the data gathered to date is that no one knows for sure just how many orphaned wells are out there. But that is changing.