I get criticism on this blog from proponents of oil and gas drilling when I write about incidents of spills and health problems related to oil and gas drilling from five or ten years ago.
They contend that new technology improvements have made modern drilling much safer than it used to be.
Today we have a new academic study that says it just isn’t true.
The peer reviewed study, entitled Assessment and risk analysis of casing and cement impairment in oil and gas wells in Pennsylvania, 2000-2012, looked at 75,505 compliance reports for 41,381 conventional and unconventional oil and gas wells in Pennsylvania drilled from January 1, 2000–December 31, 2012. The purpose was to determine methane leakage due to “compromised structural integrity of casing and cement in oil and gas wells.”
The findings were dramatic:
- Wells drilled before 2009 had a leak rate of 1%. Most of these were conventional wells, since unconventional (fracked) wells did not come on the scene until 2006.
- Newer conventional wells drilled after 2009 had a leak rate of 2%.
- Unconventional wells drilled after 2009 had a leak rate of 6%.
The leak rate for unconventional wells in the northeastern part of the state, where drilling is intense, reached as high as 10%.
The study does not explain why this is happening. According to Anthony Ingraffea of Cornell University, the lead author in the study, it could be because corners are being cut as drilling booms, because inspections are better, or because of the way the gas is trapped in the rock formation.
Robert Jackson, a professor of global environmental change at Duke University who has conducted research on methane leakage from oil and gas distribution systems but did not participate in the study, commented:
“Hydraulically fractured shale wells appear to have more problems than conventional wells. If so, it’s probably because the wells are longer, must bend to go horizontal and take more water and pressure than in the past. The combination makes well integrity a challenge.
“We can’t tell how much methane is leaking to the air based this study. That will require more work.”
According the EPA, methane (CH4) is the second most prevalent greenhouse gas emitted in the United States from human activities. In 2012, CH4 accounted for about 9% of all U.S. greenhouse gas emissions from human activities.
The study should be a big warning flag to those pushing for rapid development along the Beartooth Front. Why push for rapid development when we don’t understand the safety factors and long-term impacts?
As one Red Lodge resident put it to me last week, “What’s the rush? The shale’s still going to be there after we figure this all out.”