In situ free phase gas production in initially saturated sediment
Date
2019-04-24
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Abstract
Free-phase gas (FPG) formation and migration in gas-saturated groundwater has geological and engineering implications. FPG has been implicated in geologic overpressurizing, and in remote earthquake triggering following FPG exsolution. FPG exsolution occurs when total dissolved gas pressure (PTDG) exceeds porewater pressure (PW) and capillary pressure (PCAP), forming FPG bodies. Existing soil-water characteristic curves show the relationship between desaturation and matric potential, but neglect desaturation that occurs as a consequence of in situ FPG formation. This research sought to observe and characterize FPG production in a previously saturated zone, and measure the responses of PTGD, PW, and water content during step-function unloading of dissolved gas-charged sediment in a loading cell filled with glass beads. A revised FPG characteristic curve showing FPG formation and consumption with respect to capillary pressure is proposed here. Future work can examine these processes with revised techniques to ensure accurate measurement of capillary pressure.
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Geotechnical Engineering, Hydrogeology
Citation
Abboud, J. M. (2019). In situ free phase gas production in initially saturated sediment (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.