Underground Hydrogen Storage Research Articles

A first-order estimation of underground hydrogen storage potential in Indian sedimentary basins

Abstract Hydrogen is considered as a fuel of the future, primarily owing to its advantage of zero carbon emissions during its combustion and electricity generation. India's geographical location in the tropics and the country's government policies, which favour hydrogen, render it a potential pioneer as a hydrogen economy. Therefore, identifying suitable storage mechanisms for hydrogen in the country is crucial. In this study, we have reviewed different methodologies to estimate the potential for underground hydrogen storage in depleted hydrocarbon fields and saline aquifers. Based on our analysis, we have then estimated a first-order storage potential for underground hydrogen storage in India after applying suitable constraints. We conclude that India can store up to 22 610 terrawatt-hours (TWh) of hydrogen in deep saline aquifers. We found that the major Indian sedimentary basins, such as the Mumbai offshore, Krishna–Godavari, Rajasthan, Cauvery and Cambay basins, have high storage capacities for hydrogen on the order of 2163, 1788.8, 1211.5, 1666.6 and 342.9 TWh, respectively. We have also presented an overview of the storage potential of salt structures that are present in India. In addition to storage pathways, we have also delineated the sources that can be used in electrolysis to generate hydrogen.

Hydrogen storage in geological porous media: Solubility, mineral trapping, H2S generation and salt precipitation

Hydrogen as a significant energy vector plays an important role in the decarbonization of heavy industry. However, the intermittency and sessional availability of renewable energy sources, as well as the demand for energy at different times and places, require a medium- to long-term storage technology. Underground storage of hydrogen in depleted gas reservoirs and saline aquifers could be a good option given their storage capacity and availability in different geological settings. However, these geological porous media may suffer from many operational, geological, and geochemical complications. This paper attempts to evaluate the geochemical interactions posed by the injection of hydrogen into porous media. The results obtained from a series of thermodynamic and kinetic geochemical modeling calibrated against experimental data show that dissolution of carbonates, anhydrate and halite can occur over time, leading to precipitation of calcite, formation of H2S and long-term closure of the pore structure due to scale formation. The reduction of pyrite to pyrrhotite is likely to occur at a temperature above 90 °C, which may enhance the formation of H2S in the absence of microbial activity. The formation of scale (halite) is a long-term process that only starts after 10 years of operation due to the slow dissolution of halite in porous media. However, during hydrogen injection, salt diffusion, the formation of a dry-out zone and the phenomenon of salting out occur, depending on the salinity and temperature of the formation water. The results of this study can help to better understand and select geological porous media for large-scale hydrogen storage.

Microbial H2 Consumption by a Formation Fluid from a Natural Gas Field at High-Pressure Conditions Relevant for Underground H2 Storage.

Underground hydrogen storage (UHS) has been proposed as one option for storage of excess energy from renewable sources. Depleted gas reservoirs appear suitable, but at the same time, they may be environments with potentially high microbial abundances and activities. Hydrogen (H2) is one of the most energetic substrates in such environments, and many microorganisms are able to oxidize H2, potentially leading to loss of H2 or other unwanted reactions like production of, e.g., H2S, clogging, or corrosion. This study addressed the potential of H2 consumption by naturally abundant microorganisms in formation fluid from a gas field at near in situ pressure and temperature conditions. Microbial H2 consumption was evident at ambient and 100 bar and tolerated pressure variations reflecting cycles of H2 storage. Temperature strongly influenced the activity with higher activity at 30 °C but lower activity at 60 °C. The activity was sulfate-dependent, and sulfide was produced. The microbial community composition changed during H2 consumption with an increase in sulfate-reducing prokaryotes (SRP). Thus, the presence of an SRP-containing, H2-consuming microbial community with activity at UHS-relevant pressure and temperature conditions was shown and should be taken into account when planning UHS at this and other sites.

Understanding and challenges to de-risk storage integrity during underground hydrogen storage in depleted gas reservoirs

Understanding and challenges to de-risk storage integrity during underground hydrogen storage in depleted gas reservoirs

Microbial and Geochemical Impacts on Underground Hydrogen Storage

Microbial and Geochemical Impacts on Underground Hydrogen Storage

Оценка потенциала истощенных газовых залежей для создания подземных хранилищ водорода

In this paper, the issues of creation of a UHS in depleted gas deposits are investigated. Such facilitiesare an alternative to aquifers for the creation of a underground hydrogen storage (UHS). Based on mathematical experiments, it is shown that the use of specialized wells for water injection also contributes to the creationof a compact hydrogen storage in a depleted gas reservoir. At the same time, the creation of a UHS in a depleted gas deposit requires less energy costs, but, if possible, the reverse extraction of hydrogen turns out to be less effective than the creation of a UHS in an aquifer. In addition, the use of an already existing well stock reduces costs,but increases the likelihood of technical problems in the creation and operation of the UHS.

Underground hydrogen storage potential in Australian salt basins

Underground hydrogen storage potential in Australian salt basins

Experimental and numerical investigation of microbial growth in two-phase saturated porous media at the pore-scale

A novel approach combining microfluidics with 2-D modeling validates the proposed microbial growth model for underground hydrogen storage and concludes space-limited growth and microbial gradients on the pore scale.

Modelling of a Pilot Test of Underground Hydrogen Storage in a Depleted Gas Field in the Onshore Otway Basin

Modelling of a Pilot Test of Underground Hydrogen Storage in a Depleted Gas Field in the Onshore Otway Basin

Development of multi-objective co-optimization framework for underground hydrogen storage and carbon dioxide storage using machine learning algorithms

Underground hydrogen storage is a suitable way to create a balance between energy production and consumption. However, if it is able to incorporate a solution such as Carbon Capture and Sequestration, it has brought double benefit to the environment. Hydrogen has a good potential for energy production and transfer, and its behavior in the porous media has differences compared to other gases. In order to achieve the highest recovery factor of hydrogen and carbon dioxide storage and high utility of the project, the operational parameters of underground hydrogen storage and carbon dioxide storage should be carefully determined. The optimization of these parameters is challenging, complex, and time-consuming. Artificial intelligence methods have been developed using optimization methods in this regard. Simulation and investigation of underground hydrogen storage in depleted oil reservoirs were conducted in this study. Using machine learning methods, a proxy model for the UHS process was constructed, and then the operating parameters of UHS are optimized with the help of NSGA-II algorithm under the three objective functions of Net Present Value, hydrogen recovery factor, and CCS. Multi-layer neural networks with different architectures were trained and evaluated on the database. Research results are promising, and the approach is inspiring. It was found that the selected proxy model was able to accurately predict all three objective functions, with a R-squared of 0.9988 and a relative squared error of 0.00048. When an accurate model for NPV is not available, two-objective optimization is more efficient, but if an accurate model is available, adding NPV as a third objective function is necessary to achieve economic solutions. In both optimization perspectives, two Pareto fronts including 500 optimal solutions were determined separately. The considered NPV model correlates better with the objective function of carbon dioxide storage, while it is less consistent with the objective function of hydrogen recovery.

Review of underground hydrogen storage: Concepts and challenges

The energy transition is the pathway to transform the global economy away from its current dependence on fossil fuels towards net zero carbon emissions. This requires the rapid and large-scale deployment of renewable energy. However, most renewables, such as wind and solar, are intermittent and hence generation and demand do not necessarily match. One way to overcome this problem is to use excess renewable power to generate hydrogen by electrolysis, which is used as an energy store, and then consumed in fuel cells, or burnt in generators and boilers on demand, much as is presently done with natural gas, but with zero emissions. Using hydrogen in this way necessitates large-scale storage: the most practical manner to do this is deep underground in salt caverns, or porous rock, as currently implemented for natural gas and carbon dioxide. This paper reviews the concepts, and challenges of underground hydrogen storage. As well as summarizing the state-of-the-art, with reference to current and proposed storage projects, suggestions are made for future work and gaps in our current understanding are highlighted. The role of hydrogen in the energy transition and storage methods are described in detail. Hydrogen flow and its fate in the subsurface are reviewed, emphasizing the unique challenges compared to other types of gas storage. In addition, site selection criteria are considered in the light of current field experience. Cited as: Hematpur, H., Abdollahi, R., Rostami, S., Haghighi, M., Blunt, M. J. Review of underground hydrogen storage: Concepts and challenges. Advances in Geo-Energy Research, 2023, 7(2): 111-131. https://doi.org/10.46690/ager.2023.02.05

Geochemical modelling of hydrogen wettability on Quartz: Implications for underground hydrogen storage in sandstone reservoirs

Renewable energy particular hydrogen can be optimum solution to replace fossil fuels to achieve net-zero carbon emission targets and metigate global warming. One challenge of the hydrogen industry is to safely and economically store hydrogen. To meet this requirement, underground geological storage is a potentially suitable solution to store hydrogen in large-scale and long-term manner. Wettabillity is an important formation parameter that can affect flow behaviors of stored gas, cycling efficiency, structural and residual trap capacity. However, current research is still scarce in geochemical reactions associated hydrogen wettability alteraction in subsurface sandstone reservoirs under in-situ conditions. To fill this knowledge gap, in this study, we performed surface complexation modelling to understand the wettability of hydrogen-brine-organic acid-quartz system. The surface potential of pure quartz at various temperatures and pressure was calculated to characterize disjoining pressure isotherm. Besides, surface species concentrations of quartz and organic stearic acid were predicted to quantify the electrostatic attraction between quartz and organic acid molecues thus the hydrogen wettability on quartz surface.The modelling results show that for pure quartz, increasing temperature and pressure has a negligible effect on disjoining pressure and hydrogen wettability on the pure quartz surface, which is different from the results reported by Iglauer et al., but is in line with the results reported by Hashemi et al. When organic stearic acid is added into system, increasing organic molecules concentration and pressure strengthens the electrostatic attraction of quartz-organic acid and leads to less hydrophilicity and more hydrogen-wetting. This result is consistent with previous contact angle measurements that increasing organic acid concentration increases the brine contact angle, thus the hydrogen wettability. Our work provides a framework to characterize hydrogen wettability on mineral surface using geochemical tools to better assess the feasibility of UHS in depleted sandstone reservoirs.

Prospects for the Implementation of Underground Hydrogen Storage in the EU

The hydrogen economy is one of the possible directions of development for the European Union economy, which in the perspective of 2050, can ensure climate neutrality for the member states. The use of hydrogen in the economy on a larger scale requires the creation of a storage system. Due to the necessary volumes, the best sites for storage are geological structures (salt caverns, oil and gas deposits or aquifers). This article presents an analysis of prospects for large-scale underground hydrogen storage in geological structures. The political conditions for the implementation of the hydrogen economy in the EU Member States were analysed. The European Commission in its documents (e.g., Green Deal) indicates hydrogen as one of the important elements enabling the implementation of a climate-neutral economy. From the perspective of 2050, the analysis of changes and the forecast of energy consumption in the EU indicate an increase in electricity consumption. The expected increase in the production of energy from renewable sources may contribute to an increase in the production of hydrogen and its role in the economy. From the perspective of 2050, discussed gas should replace natural gas in the chemical, metallurgical and transport industries. In the longer term, the same process will also be observed in the aviation and maritime sectors. Growing charges for CO2 emissions will also contribute to the development of underground hydrogen storage technology. Geological conditions, especially wide-spread aquifers and salt deposits allow the development of underground hydrogen storage in Europe.

Simulation of the inelastic deformation of porous reservoirs under cyclic loading relevant for underground hydrogen storage

Subsurface geological formations can be utilized to safely store large-scale (TWh) renewable energy in the form of green gases such as hydrogen. Successful implementation of this technology involves estimating feasible storage sites, including rigorous mechanical safety analyses. Geological formations are often highly heterogeneous and entail complex nonlinear inelastic rock deformation physics when utilized for cyclic energy storage. In this work, we present a novel scalable computational framework to analyse the impact of nonlinear deformation of porous reservoirs under cyclic loading. The proposed methodology includes three different time-dependent nonlinear constitutive models to appropriately describe the behavior of sandstone, shale rock and salt rock. These constitutive models are studied and benchmarked against both numerical and experimental results in the literature. An implicit time-integration scheme is developed to preserve the stability of the simulation. In order to ensure its scalability, the numerical strategy adopts a multiscale finite element formulation, in which coarse scale systems with locally-computed basis functions are constructed and solved. Further, the effect of heterogeneity on the results and estimation of deformation is analyzed. Lastly, the Bergermeer test case-an active Dutch natural gas storage field-is studied to investigate the influence of inelastic deformation on the uplift caused by cyclic injection and production of gas. The present study shows acceptable subsidence predictions in this field-scale test, once the properties of the finite element representative elementary volumes are tuned with the experimental data.

Hydrogen storage in gas reservoirs: A molecular modeling and experimental investigation

Hydrogen is one of the clean energy sources that can be used instead of fossil fuel sources to reduce greenhouse emissions. However, hydrogen supply intermittency significantly reduces the deployment and reliability of this energy resource. Therefore, this work investigates the underground storage of hydrogen in depleted gas reservoirs to avoid seasonal fluctuations in hydrogen supply and assure long-term energy security. The obtained results from molecular simulation (Density Functional Theory) revealed hydrogen is adsorbed physically on calcite (104) and silica (001) surfaces on different adsorption configurations. This conclusion is supported by low adsorption energies (−0.14 eV for calcite and −0.09 for silica) and by Bader charge analysis, which showed no indication of charge transfer. The experimental results illustrated that hydrogen has a very low adsorption affinity toward carbonate and sandstone rocks in the temperature range of 50–100 °C and pressure up to 20 bar. These results show the potential of depleted gas reservoirs to store hydrogen for s is useful in hydrogen recovery as no hydrogen will be adsorbed to the rock surface of conventional gas reservoirs.

Hydrogen Diffusion in Organic-Rich Porous Media: Implications for Hydrogen Geo-storage

Subsurface hydrogen storage for large-scale energy supply to decarbonize a variety of greenhouse gas-emitting activities is gaining momentum worldwide to combat climate change. Hydrogen’s extensive range of flammable concentrations and low minimum ignition energy in air combined with its highly diffusive nature mandate implementation of comprehensive risk management protocols to maintain storage safety. In particular, the role of hydrogen diffusion process (self-diffusion) needs further investigation to understand H2 transport behavior and elude the associated risk of leakage for the long-term safety of the underground hydrogen storage process. Recent molecular simulation studies suggest that, compared to other subsurface storage options, depleted shale reservoirs may offer preferential storage characteristics due to excellent sealing and adsorption capabilities of shale. Data on hydrogen diffusion in organic (kerogen)-rich shale is scarce. Here, we applied molecular dynamics to compute hydrogen self-diffusivity in kerogen systems with different structures at various pressures, ranging from 3 to 41 MPa, and under an isothermal condition of 360 K. Two kerogen types of varying maturity (II-A and II-C) were utilized to create slit nanopores of 0.5 and 2 nm in size. The Knudsen number was calculated based on the mean free path and determined by the density values obtained from simulation to improve diffusion coefficient estimates. Results obtained indicate the Kn data in the range from 0.64 to 9.72, demonstrating that the main transport mechanism was transitional in nature. With increasing pressure, diffusivity declined regardless of the slit pore size or kerogen type. H2 diffusion was greater for the 2 nm pore system compared to both the 0.5 nm in II-A (0.004–0.02 cm2/s) and II-C (0.0037 to 0.019 cm2/s). In addition, for a fixed nanopore size, thermal maturity does not seem to impact diffusivity. Finally, simulation results were regressed to delineate a continuous description for diffusivity as a function of pressure. For curve fitting, R2 values were found to be 98 and 92% for 2 nm pore size of II-A and II-C, respectively, while 97 and 79% for 0.5 nm pore size of II-A and II-C, respectively. The results obtained are not only of interest for storage of hydrogen in shale but also for any subsurface hydrogen storage approach where a shale layer acts as a seal to form a trap.

Pore-scale modeling of multiphase flow in porous media using a conditional generative adversarial network (cGAN)

Multiphase flow in porous media is involved in various natural and industrial applications, including water infiltration into soils, carbon geosequestration, and underground hydrogen storage. Understanding the invasion morphology at the pore scale is critical for better prediction of flow properties at the continuum scale in partially saturated permeable media. The deep learning method, as a promising technique to estimate the flow transport processes in porous media, has gained significant attention. However, existing works have mainly focused on single-phase flow, whereas the capability of data-driven techniques has yet to be applied to the pore-scale modeling of fluid–fluid displacement in porous media. Here, the conditional generative adversarial network is applied for pore-scale modeling of multiphase flow in two-dimensional porous media. The network is trained based on a data set of porous media generated using a particle-deposition method, with the corresponding invasion morphologies after the displacement processes calculated using a recently developed interface tracking algorithm. The results demonstrate the capability of data-driven techniques in predicting both fluid saturation and spatial distribution. It is also shown that the method can be generalized to estimate fluid distribution under different wetting conditions and particle shapes. This work represents the first effort at the application of the deep learning method for pore-scale modeling of immiscible fluid displacement and highlights the strength of data-driven techniques for surrogate modeling of multiphase flow in porous media.

Hydrogen Technology Development and Policy Status by Value Chain in South Korea

Global transitions from carbon- to hydrogen-based economies are an essential component of curbing greenhouse gas emissions and climate change. This study provides an investigative review of the technological development trends within the overall hydrogen value chain in terms of production, storage, transportation, and application, with the aim of identifying patterns in the announcement and execution of hydrogen-based policies, both domestically within Korea, as well as internationally. The current status of technological trends was analyzed across the three areas of natural hydrogen, carbon dioxide capture, utilization, and storage technology linked to blue hydrogen, and green hydrogen production linked to renewable energy (e.g., water electrolysis). In Korea, the establishment of underground hydrogen storage facilities is potentially highly advantageous for the storage of domestically produced and imported hydrogen, providing the foundations for large-scale application, as economic feasibility is the most important national factor for the provision of fuel cells. To realize a hydrogen economy, pacing policy and technological development is essential, in addition to establishing a roadmap for efficient policy support. In terms of technological development, it is important to prioritize that which can connect the value chain, all of which will ultimately play a major role in the transformation of human energy consumption.

The effect of clay on initial and residual saturation of hydrogen in clay-rich sandstone formation: Implications for underground hydrogen storage

Understanding wettability in rock-brine-hydrogen systems is essential for dependable predictions of capillary/residual trapping in clay-rich sandstone formations. Despite being the most used technique, wettability assessment based on contact angle measurements is confronted with inherent uncertainties that limit its reliability. In contrast, core flooding techniques provide a more direct and realistic picture of wettability and its time evolution. Nuclear Magnetic Resonance (NMR) allows us to evaluate the initial and residual hydrogen saturations and distribution along the core specimen. It is a fast, reliable, and effective way of inferring the impact of wettability on hydrogen migration, and residual trapping in prospective geo-storage rock formations. Recent publications have reported the evaluation of wettability in a brine-hydrogen-rock system where the rock is a clean sandstone (no clays). Here we evaluate the impact of the presence of clays in a sandstone, which has not been reported yet. NMR monitoring was employed to characterize the initial and residual hydrogen saturations in the Bandera Grey (BG) sandstone. To investigate the impact of clay minerals on hydrogen saturation, same rock sample was characterized in its natural state, and after heating it to 700 °C for 12 h in an air environment to burn off clay minerals, During the NMR core flooding experiments, ten pore volumes (PVs) were injected/withdrawn during the drainage/imbibition cycles at a fluid injection rate of 2 mL/min under room temperature and 1000 psi confining pressure. Due to the hydrophilicity of quartz and clay, the tested BG sandstone (clay-rich sandstone) shows a significant residual/trapped saturation (∼3.5% can be reproduce); therefore, clay-rich sandstone may not be ideal for hydrogen storage unless cushion gas is used.The results show that initial and residual hydrogen saturations were slightly changed after firing (from 16% to 18% for initial and from 14% to 13% for residual). This also suggests that the wettability of the BG sandstone-brine-hydrogen system is slightly impacted by clay content and type. We also observed that clay firing at 700 °C has little effect on the porosity and gas permeability of the BG sandstone. Moreover, X-ray powder diffraction (XRD) results showed that quartz content increases from 68.1% to 76.2%, Kaolinite transformed into illite and clinochlore disappeared. The disappearance of chlorite after firing suggests that it is transformed into another clay type.

Experimental investigation of hydrogen-carbonate reactions via computerized tomography: Implications for underground hydrogen storage

The underground hydrogen storage (UHS) in depleted hydrocarbon reservoirs, aquifers, and saline caverns is regarded as a vital component of hydrogen economy value-chains, meant to tackle carbon emissions and global warming. The caprock integrity and storage capacity of the carbonate formations can be altered by the reaction between the injected hydrogen and the calcite/dolomite minerals during UHS. However, experimental investigations of hydrogen-calcite/dolomite reactions at underground storage temperature are rarely reported in literature. Thus, we conducted X-ray computed micro-tomography (μCT) scans of limestone and dolomite cores before and after pressurization with hydrogen for 75 days at 700 psi and 75 °C. For the first time, a significant calcite expansion was observed and led to reduction in storage capacity (i.e., effective porosity) by 47%. However, the storage capacity of the dolomite rock slightly increased (∼6%) because the grain expansion effects canceled out the dissolution effects. The study suggests that reduction in storage capacity of carbonate formation due to hydrogen reactivity with calcite is possible during UHS in carbonate formations. Thus, hydrogen reactivity with carbonate minerals should be evaluated to de-risk hydrogen storage projects in carbonate formations.