Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences


Geology and Geography

Committee Chair

Shikha Sharma

Committee Member

Vikas Agrawal

Committee Member

Alexandra Hakala

Committee Member

Timothy Carr


Natural gas extracted from tight shale formations, such as the Marcellus Shale, represent an important and developing front in energy exploration. By fracturing these formations using pressurized fracturing fluid, previously unobtainable hydrocarbon reserves may be tapped. While pursuing this resource hydraulic fracturing operations leave chemically complex fluids in the shale formation for at least two weeks. This provides a substantial opportunity for the hydraulic fracturing fluid (HFF) to react with the shale formation at reservoir temperature and pressure. In this study, we investigated the effects of the carbonates on shale-HFF reactions with a focus on the Marcellus Shale. We determined the effects of carbonate minerals on shale-HFF reactions by performing autoclave experiments at high reservoir temperature and pressure conditions using a carbonate-rich and carbonate free shale sample. We observed that carbonate minerals not only directly controlled the pH of the solution but also had a range of secondary effects on oxidizing efficacy of breakers, iron controlling ability of citric acid, mineral dissolution, and organic matter oxidation. As a consequence, the carbonate minerals had a broad influence on shale-HFF interactions. These interactions can potentially affect the shale porosity, the well’s microfracture integrity, and the release of heavy metals and volatile organic contaminants in the produced water released on the surface.

Included in

Geochemistry Commons