Mutaz Alsubhi
Ph.D Candidate
King Abdullah University of Science and Technology (KAUST)
Mutaz is a Ph.D. researcher at KAUST specializing in energy resources and petroleum engineering. His work centers on advancing underground storage solutions for Liquid Organic Hydrogen Carriers (LOHC) and underground hydrogen storage. Through experimental and modeling approaches, he aims to improve the safety, efficiency, and scalability of future hydrogen-based energy systems.
Participates in
TECHNICAL PROGRAMME | Energy Technologies
Research, Technology Start-ups and Funding
Forum 19 | Technical Programme Hall 4
27
April
15:00
16:30
UTC+3
The shift to a sustainable hydrogen economy is vital, with underground LOHC storage presenting a pioneering approach for secure and large-scale hydrogen storage. The implementation of large-scale underground hydrogen storage using liquid organic hydrogen carriers (LOHCs) requires comprehensive reservoir modeling that captures the complete storage and retrieval cycle of both lean and hydrogenated carriers. This study presents an advanced reservoir simulation approach that utilizes pore network model-derived relative permeability data to evaluate the performance of toluene and methylcyclohexane (MCH) injection and production in subsurface formations, representing an operational scenario for LOHC storage systems.
Building upon detailed pore-scale characterization through micro-CT imaging and pore network modeling of Berea sandstone, relative permeability and capillary pressure curves were derived for both toluene-brine and MCH-brine systems through multiphase displacement simulations. These pore-scale derived flow functions, which incorporate experimentally measured wettability and interfacial tension properties, were upscaled and integrated into a comprehensive reservoir simulation framework implemented in CMG-GEM. The simulation approach represents a significant advancement over single-well studies by modeling the simultaneous operation of two injection wells within a shared reservoir system, enabling evaluation of the complete LOHC storage cycle, including both hydrogen loading (toluene injection) and storage (MCH injection) phases.
The reservoir model was designed to simulate field-scale with two strategically positioned injection wells: one for toluene injection during hydrogen loading phases and another for MCH injection during hydrogen storage phases. This dual-well configuration enables the simulation of complete operational cycles where toluene is injected and subsequently converted to MCH through hydrogenation, followed by MCH storage and eventual dehydrogenation back to toluene for hydrogen release. The model incorporates heterogeneous reservoir properties, realistic boundary conditions, and operational constraints to represent actual subsurface storage scenarios. Multiple injection-production cycles were simulated to evaluate long-term storage performance, including assessment of fluid distribution patterns, pressure evolution, and storage efficiency metrics.
Simulation results demonstrate the feasibility of simultaneous LOHC operations within a single reservoir system, revealing distinct flow behaviors and storage characteristics for each carrier. The toluene injection well exhibited superior sweep efficiency and faster pressure equilibration due to its more favorable wettability characteristics, while the MCH injection well showed different displacement patterns consistent with its distinct interfacial properties. The dual-well approach enables optimization of injection strategies, well placement, and operational scheduling to maximize storage capacity utilization while maintaining reservoir integrity. The simulations provide critical insights into interference effects between wells, optimal spacing requirements, and the impact of reservoir heterogeneity on storage performance.
This work represents the first comprehensive reservoir simulation study to model the complete LOHC storage cycle using pore network-derived flow functions in a dual-well configuration. The methodology provides a robust framework for designing and optimizing commercial-scale underground LOHC storage facilities, supporting the development of economically viable hydrogen storage infrastructure that can accommodate the full spectrum of LOHC operations required for large-scale energy storage applications.
Co-author/s:
Zeeshan Tariq, Research Scientist, King Abdullah University of Science and Technology (KAUST).
Nasendra Kumar, Postdoc, King Abdullah University of Science and Technology (KAUST).
Dr. Muhhamad Ali, Research Scientist, King Abdullah University of Science and Technology (KAUST).
Building upon detailed pore-scale characterization through micro-CT imaging and pore network modeling of Berea sandstone, relative permeability and capillary pressure curves were derived for both toluene-brine and MCH-brine systems through multiphase displacement simulations. These pore-scale derived flow functions, which incorporate experimentally measured wettability and interfacial tension properties, were upscaled and integrated into a comprehensive reservoir simulation framework implemented in CMG-GEM. The simulation approach represents a significant advancement over single-well studies by modeling the simultaneous operation of two injection wells within a shared reservoir system, enabling evaluation of the complete LOHC storage cycle, including both hydrogen loading (toluene injection) and storage (MCH injection) phases.
The reservoir model was designed to simulate field-scale with two strategically positioned injection wells: one for toluene injection during hydrogen loading phases and another for MCH injection during hydrogen storage phases. This dual-well configuration enables the simulation of complete operational cycles where toluene is injected and subsequently converted to MCH through hydrogenation, followed by MCH storage and eventual dehydrogenation back to toluene for hydrogen release. The model incorporates heterogeneous reservoir properties, realistic boundary conditions, and operational constraints to represent actual subsurface storage scenarios. Multiple injection-production cycles were simulated to evaluate long-term storage performance, including assessment of fluid distribution patterns, pressure evolution, and storage efficiency metrics.
Simulation results demonstrate the feasibility of simultaneous LOHC operations within a single reservoir system, revealing distinct flow behaviors and storage characteristics for each carrier. The toluene injection well exhibited superior sweep efficiency and faster pressure equilibration due to its more favorable wettability characteristics, while the MCH injection well showed different displacement patterns consistent with its distinct interfacial properties. The dual-well approach enables optimization of injection strategies, well placement, and operational scheduling to maximize storage capacity utilization while maintaining reservoir integrity. The simulations provide critical insights into interference effects between wells, optimal spacing requirements, and the impact of reservoir heterogeneity on storage performance.
This work represents the first comprehensive reservoir simulation study to model the complete LOHC storage cycle using pore network-derived flow functions in a dual-well configuration. The methodology provides a robust framework for designing and optimizing commercial-scale underground LOHC storage facilities, supporting the development of economically viable hydrogen storage infrastructure that can accommodate the full spectrum of LOHC operations required for large-scale energy storage applications.
Co-author/s:
Zeeshan Tariq, Research Scientist, King Abdullah University of Science and Technology (KAUST).
Nasendra Kumar, Postdoc, King Abdullah University of Science and Technology (KAUST).
Dr. Muhhamad Ali, Research Scientist, King Abdullah University of Science and Technology (KAUST).
