Field Scale Modeling Of Bio-Reactions During Underground Hydrogen Storage
B. Hagemann, L. Ganzer and M. Panfilov
Event name: ECMOR XVI - 16th European Conference on the Mathematics of Oil Recovery
Session: Physical Modelling II
Publication date: 03 September 2018
Info: Extended abstract, PDF ( 1.35Mb )
Price: € 20
The energy transition from fossil and nuclear energy towards an energy supply system from renewable sources will require an enormous extension of the existing energy storage capacity. For this intention depleted oil and gas reservoirs could play a key role when they are used as storage reservoirs for hydrogen or other energy carriers in a seasonal or more frequent cycle. In previous studies it was shown that chemical reactions catalyzed by anaerobic microorganisms and mixing phenomena between gases with different composition have important influences in underground storage of hydrogen. In particular hydrogenotrophic microorganisms could produce methane by metabolizing hydrogen and carbon dioxide. To describe these effects a model was developed which couples the compositional two-phase transport of gas and water to microbial population dynamics and bio-chemical reactions. In this work the numerical model was applied to a field scale storage scenario using a real geological model and several storage operation wells. The complex multi-physical model applied on around 200.000 grid cells results in approximately 2 million degrees of freedom. In addition the strong coupling between the microbial population dynamics and transport of chemical components is numerically difficult to handle and consequently small times steps not larger than one or two days have to be calculated. To overcome the computational effort the simulation study was executed on a high performance computing cluster. The interpretation of the simulation results shows that a significant amount of the stored hydrogen was transformed into methane due to the bio-chemical reactions. In addition it was demonstrated that the produced gas contains H2S in the range of some parts per thousand when sulfate reducing bacteria were present.