Blar i UiS Brage på forfatter "Helland, Johan Olav"
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A pore-to-core scale investigation of hysteresis for CO2 storage processes using a discrete-domain method
Engarnevis, Nazila (Master thesis, 2022)In this thesis we have studied a discrete-domain method that is implemented to demonstrate the immiscible, two-phase displacements of two fluids, namely CO2 and water (or brine) in an originally water-saturated reservoir ... -
Adaptive mesh refinement in locally conservative level set methods for multiphase fluid displacements in porous media
Singh, Deepak; Friis, Helmer André; Jettestuen, Espen; Helland, Johan Olav (Peer reviewed; Journal article, 2023)Multiphase flow in porous media often occurs with the formation and coalescence of fluid ganglia. Accurate predictions of such mechanisms in complex pore geometries require simulation models with local mass conservation ... -
Footprints of spontaneous fluid redistribution on capillary pressure in porous rock
Helland, Johan Olav; Friis, Helmer Andre`; Jettestuen, Espen; Skjæveland, Svein Magne (Journal article; Peer reviewed, 2017-05)Pore-scale imaging of two-phase flow in porous media shows that pore filling occurs as cooperative events with accompanying spontaneous fluid redistribution in other parts of the pore space. We present a level set method ... -
A level set approach to Ostwald ripening of trapped gas bubbles in porous media
Singh, Deepak; Friis, Helmer André; Jettestuen, Espen; Helland, Johan Olav (Peer reviewed; Journal article, 2022)Ostwald ripening of gas bubbles is a thermodynamic process for mass transfer, which is important for both foam enhanced oil recovery and geological CO2 storage. We present a methodology for simulating Ostwald ripening of ... -
Machine learning for underground gas storage with cushion CO2 using data from reservoir simulation
Helland, Johan Olav; Friis, Helmer André; Assadi, Mohsen; Nagy, Stanislaw (Peer reviewed; Journal article, 2023)Underground natural gas storage (UNGS) is a means to store energy temporarily for later recovery and use. In such storage operations, carbon dioxide (CO2) can be injected as cushion gas to improve the operating efficiency ... -
Ostwald ripening of trapped gas bubbles in porous media : A pore-scale perspective
Singh, Deepak (PhD thesis UiS;747, Doctoral thesis, 2024)Ostwald ripening of gas bubbles is a thermodynamic process for mass transfer, which is significant for both foam-enhanced oil recovery and underground gas storage. During recovery, it can impact the macroscopic efficiency. ... -
Pore-scale Ostwald ripening of gas bubbles in the presence of oil and water in porous media
Singh, Deepak; Friis, Helmer André; Jettestuen, Espen; Helland, Johan Olav (Peer reviewed; Journal article, 2023)Hypothesis Ostwald ripening of gas bubbles is a spontaneous mass transfer process that can impact the storage volume of trapped gas in the subsurface. In homogeneous porous media with identical pores, bubbles evolve toward ... -
Prediction of Optimal Production Time during Underground CH4 Storage with Cushion CO2 Using Reservoir Simulations and Artificial Neural Networks
Helland, Johan Olav; Friis, Helmer André; Assadi, Mohsen; Klimkowski, Lukasz; Nagy, Stanislaw (Peer reviewed; Journal article, 2023)Injection of carbon dioxide (CO2) in aquifers for underground natural gas storage (UNGS) can improve the operating efficiency of the storage facility during gas injection and production and later serve as a solution for ...