Public data from three big producing states has found that some wells drilled before 2018, particularly directional wells used often in unconventional plays, may have integrity issues that could cause internal leaks. 

NETL rig

Led by researchers at the U.S. Department of Energy’s National Energy Technology Laboratory (NETL), the new report compiled more than 470,000 regulatory records from well integrity tests in Colorado, New Mexico, and Pennsylvania on 100,000-plus wells drilled before 2018. The research was published in the Proceedings of the National Academy of Sciences.

“We mined publicly available records from state regulatory databases and synthesized the results of various well testing methods into a uniform dataset that describes the integrity of 105,031 wells,”...