Social, legal and health issues related to air and water toxic pollution in Australia.


Postby HVPA_research » Thu Oct 07, 2010 6:47 am

HVPA Link: http://forum.huntervalleyprotectionalliance.com/viewtopic.php?f=3&t=243
The gas industry has claimed for years that cross contamination of different horizontal aquifers is impossible because their gaswells are sealed with cement. The following links to research papers show that for almost a decade the industry had known that these cements seals are not perfect and that the cement deteriorates even during the life time of the well. Yet the Australian coal seam gas claims that contamination of the Great Artesian Basin by their activities is unlikely if not impossible.

Just forwarding you an email I sent to GABCC people a month ago, re cement deterioration. Further to what Ian Hansen was saying about lack of any supervision, and further to what Heath was saying that the drillers out at Nymagee told him (about not cementing off the holes) - it appears that even if the industry WERE supervised, and made to cement the holes off properly, the cement will only last about 15 years anyway.
Neil said ages ago, that no plumbing (and fittings) ever last for ever. No infrastructure is as strong and well constructed as railway line, yet it buckles and cracks and corrodes with time. This concrete and pipe (to case the bores) is going through the saltiest, most corrosive layers of soil and water, and it is laughable to suggest it will last forever.
The only way to protect the GAB and aquifers from incredible pollution, migrating chemicals, and inter-aquifer leakage and contamination, is to stop the csg industry. Full stop.

Sent: Monday, September 06, 2010 10:59 AM
Subject: Cement deterioration

I believe this is of enormous concern, with a projected 40,000 holes (csg testing etc.) to be drilled into the GAB - and with information that cementing them off will not be effective long term.

"Cementing and completion practices in the two basins are the main risks to the downhole environment. Many mechanisms are present to cause the cement to deteriorate. As a result, sufficient zonal isolation cannot be guaranteed for an infinite amount of time. The major risk associated with cement failure is cement carbonation."

http://www.pir.sa.gov.au/__data/assets/ ... _risks.pdf

This seems to back up one of the conclusions of the US UPA incident paper (link below) - ie that cementing of boreholes only lasts about 15 years.

US EPA incident reports of CSG impact,
http://www.epa.gov/ogwdw000/uic/pdfs/cb ... idents.pdf

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