Modelling Biogenic Coal Gas Processes
Date
2015-05-29
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Abstract
The research documented in this thesis deals with geological and reservoir simulation modelling of coal bed methane recovery processes and biogenic coal gas processes. The target coal beds are too deep to be mined by conventional mining technologies but can be used to effectively and economically produce natural gas. With biogenic stimulation, there is potential that these reservoirs can produced additional gas – this would be useful to extend the life of coal bed methane wells. North America has huge coal reserves with reserves-to-production ratio of 250 years when compared to other fossil fuels. In Canada, most of these coal beds lies in deeper reservoirs therefore focus of this work is to perform the numerical simulation of recovery processes for deep coal beds and enhanced bioconversion of coal to gas. In the research done here, first, an ultrarefined coal bed geological model is constructed with input data derived from logs, core, core photos, adsorption isotherms, and gas composition analysis. This model reveals the structure of the underground coal beds and shows that they are heterogeneous with respect to their placement, size, and depth. These models inform on how to place wells for recovery process design. In the second part of the research, the geological model is converted into a reservoir simulation model which, after being calibrated against field data, is used to evaluate the ability to enhance gas rates by enhancing biogenic gas generation rates within the reservoir by injecting nutrient into the reservoir. The results show that the biogenic gas rates depend on the residence time of the injected nutrient – the larger the residence time, the greater the gas production rate.
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Engineering--Petroleum
Citation
Batwara, A. (2015). Modelling Biogenic Coal Gas Processes (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/26954