More on Explosion / Gas in Well Water

There is a recent Gannet news report on gas from Devonian shale formations (which includes the Marcellus shale) being found in four drinking water wells in Susquehanna County, PA. How did gas gas from 6,000 feet deep make its way into ground water near the surface? According to this article, one theory is that gas traveled up gas well bores and leaked out through the annular spacing between the smaller well pipe and the larger surface drill hole. I recommend visiting the West Virginia Surface Owners’ Rights Organization website on “How a gas well is drilled down into the ground, and what can go wrong” to further understand how this could happen. I am illustrating the theory the PA DEP is currently pursuing with a few relevant slides from their website.

How Cementing of a Casing Can Be Compromised
How Cementing of a Casing Can Be Compromised

How the Gas Bore Hole relates to the Annular Space
How the Gas Bore Hole relates to the Annular Space

Susan Riha, WRI Director

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3 Responses to More on Explosion / Gas in Well Water

  1. Brian says:

    As a professional geologist, I like the grouting technique:
    Where I have concerns are as follows:
    1. Placement of casing and adequately separating the freshwater and saline, brine, or connate water.
    2. Sealing off shallow gas deposits in the lower portion of the freshwater aquifer.
    3. Applying to much pressure when hydrofracturing.
    4. Not allowing enough time for grout to cure.
    5. Making sure the annulus is properly grouted.

    I discuss these in my blog.


    Brian Oram, PG
    B.F. Environmental Consultants Inc.

  2. I forgot to mention that the blue image at the base of the drawing is a little misleading. The Marcellus Shale does contain water, but this is water that has been trapped in the formation during deposition. This water is not part of the freshwater or shallow saline water flow system.

    The primary concern with Marcellus Shale is the need for multiple strings or casings to seal of the freshwater, saline water, and deeper formations that may contain brine or other gases.

    Also – I should have used the word cement over grout.

    Just my thoughts

  3. After decades of deal making between government and the industry it has resulted in exemptions for the oil and gas companies from protections in the clean water act, the environmental response, compensation, and liability act (CERCLA also known as the Superfund law), the resource Conservation and recovery act, and the Safe Drinking Water Act. Also, the gas industry is not covered by public right to know provisions, which mean companies can withhold information about the chemicals they use in the “fracking” process.

    Dan Puroclean

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