Vertical Movement of Hydraulic Fracturing Fluids in the Karoo Formations of South Africa

Some of the findings from research done by Prof Gerrit van Tonder and Fanie de Lange at the Institute for Groundwater Studies:

A number of factors will determine if the hazardous hydraulic fracturing fluids will move from the deep organic rich shale layers in the Ecca formation of South Africa, towards, and into the shallow fresh water aquifer.

The primary aim of the study was to prove that there is an upward vertical flow gradient between the deep layers in the Karoo and the top fresh water aquifer. The authors proved without any doubt that an upward vertical flow gradient exists.

The exact role that dolerite and sills will play in the upward movement of fracking chemicals is uncertain at this stage. Our greatest concern currently is the faulty fracking boreholes, and to be more specific, the cement annalus situated between the casing and the rock formation. If there are 50 000 well pads, there must be at least 50 000 boreholes and each of these boreholes must be considered a potential preferred pathway for fracking chemicals, diluted formation elements and methane. The more boreholes, the greater the risk of pollution.

Conclusion: Under no circumstances must the companies be allowed to include any hazardous chemicals into the fracking fluid cocktail.

This module must be validated with field data.

Geochemical evidence for possible natural migration of Marcellus Formation brine to shallow aquifers in Pennsylvania

PNAS, Proceedings of the National Academy of Sciences of the United States of America

Nathaniel R. Warner, Robert B. Jackson, Thomas H. Darrah, Stephen G. Osborn, Adrian Down, Kaiguang Zhao, Alissa White, and Avner Vengosh

The debate surrounding the safety of shale gas development in the Appalachian Basin has generated increased awareness of drinking water quality in rural communities. Concerns include the potential for migration of stray gas, metal-rich formation brines, and hydraulic fracturing and/or flowback fluids to drinking water aquifers. A critical question common to these environmental risks is the hydraulic connectivity between the shale gas formations and the overlying shallow drinking water aquifers. We present geochemical evidence from northeastern Pennsylvania showing that pathways, unrelated to recent drilling activities, exist in some locations between deep underlying formations and shallow drinking water aquifers.

Geochemical evidence.


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