The number of earthquakes rattling the U.S. shale patch is growing exponentially as producers pump massive amounts of dirty water from their oil and gas wells back underground.
Tremors registering at least a 2 on the Richter scale quadrupled from 2017 levels to a record 938 last year and are on pace to top that this year, according to a Rystad Energy analysis of data in Oklahoma, Texas, Louisiana and New Mexico. Though earthquakes have long been linked to activity related to shale production, the report provides more evidence of the connection in the U.S. Southwest, where oil drilling has intensified in the past decade.
Last year’s jump in earthquakes came even as production tumbled amid the pandemic and the amount of wastewater injected into disposal wells slipped. But water disposal — the biggest culprit behind earthquakes in oil and gas fields — climbed sharply from 2011 through 2019 to more than 12 billion barrels, creating conditions that can make the ground more unstable overall.
The increased tremors and huge volumes of wastewater have added to environmental concerns surrounding oil and gas production from shale fields. Drillers have come under increasing scrutiny in recent years, with companies under pressure from investors to disclose climate risks and reduce greenhouse gas emissions.