Study shows newer wells leak much more methane than older ones

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.

Marcellus Shale gas well.  Courtesy of Gerry Dincher

Marcellus Shale gas well.
Courtesy of Gerry Dincher (click to enlarge)

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%.

A lump of shale rock -- it's not going anywhere

A lump of shale rock — it’s not going anywhere

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.”

Sources of methane emissions (Source: EPA)

Sources of methane emissions (Source: EPA)

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.”

About davidjkatz

The Moses family has lived on the Stillwater River since 1974, when George and Lucile Moses retired and moved to the Beehive from the Twin Cities. They’re gone now, but their four daughters (pictured at left, on the Beehive) and their families continue to spend time there, and have grown to love the area. This blog started as an email chain to keep the family informed about the threat of increased fracking activity in the area, but the desire to inform and get involved led to the creation of this blog.
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1 Response to Study shows newer wells leak much more methane than older ones

  1. S. Thomas Bond says:

    Here in the Marcellus it is widely believed the simple “layer cake” diagrams we see of shale drilling represent the actual conceptualizations of geologists guiding the drilling of shale wells. There is no consideration of cracks between the layers in planning, in part because they are undetected with present science, and in part because of long held belief such extensive cracks do not exist.

    “Communication” between shale wells and older, shallower wells so that the old wells show much greater production after fracking, is a well-established phenomenon. In a few places the gas comes to the surface, showing itself in bubbles and dead vegetation. This is another sign these cracks exist in addition to the common loss of potable water.

    This is a problem that the companies can only ignore, because there is no way to detect or visualize the cracks by which gas and fluids come to the surface outside the well. From the drilling company point of view it is “ya pays yer money and ya takes yer chances, ” as they say at the carnival.

    Since shale drilling is finance driven, that is, pushed largely by those who aggregate capital, and those who seek quick profit, and to a somewhat lesser degree by those who seek to build a national empire, a little sacrifice from those of us who live in rural areas is not too much to ask. They and their families are not affected.

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