Storage Reservoir Research Articles

Numerical Simulation Study of the Optimization on Tubing-to-Sediment Surface Distance in Small-Spacing Dual-Well (SSDW) Salt Caverns

The small-spacing dual-well (SSDW) technique plays a crucial role in the establishment of underground salt cavern gas storage reservoirs. However, during the cavity dissolution and brine discharge processes, insoluble sediment is prone to being carried into the discharge tubing with the brine, leading to tubing blockages or clogging, which disrupts injection and withdrawal operations and severely affects both project efficiency and the safety of the gas storage facility. This study systematically analyzes the influence of the gap between the injection and discharge tubing and the surface of the sediment-on-sediment movement, deposition, and tubing safety in SSDW salt caverns. Through numerical simulations, this study investigates the influence of tubing layout on the internal flow field distribution of the cavern and the suspension behavior of sediment, revealing the changing trend of the risk of sediment entering the tubing at different distances. The results show that a rational tubing distance can significantly lower the risk of sediment backflow and tubing entry, while maintaining high brine discharge efficiency. Based on the simulation results, an optimized tubing layout design suitable for SSDW salt caverns is proposed, offering technical direction to guarantee the safe and effective functioning of underground salt cavern gas storage sites.

Calcium carbonate sediment corrosion and formation investigation in drinking water distribution network in Sough City, Iran

One of the major problems facing the water industry is corrosion and sedimentation, which causes problems such as reduced water quality and the useful life of water supply network equipment. This study aimed to investigate the corrosion and sediments formed in the drinking water distribution network of Sough City. In this cross-sectional study, samples were prepared from 7 wells, water storage reservoirs, and a dedicated water supply network in this area from 2006 to 2017. The parameters included pH, TDS, water temperature, total alkalinity, calcium hardness, and total hardness indices of Langelier, Ryznar, Pokurious, and Aggressive were measured in all sources. The mean indices were -0.59 ± 0.62, 8.48 ± 0.79, 7.24 ± 0.28, and 12.01 ± 0.22, respectively. The average PSI in all seasons was more than 7, AI was equal to 12, and pH in all seasons was 7.8, but in the summer it increased slightly to 8.5. This research showed that the amount of corrosiveness and sedimentation of water is not related to physicochemical parameters. Examination of corrosion indices of the dedicated water supply network of Sough City in the summer of 2011 showed that the water of this network tends to calcium carbonate sedimentation. A magnetic field was used to remove sediments formed in this water distribution network.

Numerical Simulation of Gas–Liquid–Solid Erosive Wear in Gas Storage Columns

Gas reservoirs play an increasingly important role in oil and gas consumption and safety in China. To study the problem of erosion and wear caused by gas-carrying particles in the process of gas extraction from gas storage reservoirs, a mathematical model of gas–liquid–solid three-phase erosion of gas storage reservoir columns was established through theories of multiphase flow and particle motion. Based on this model, the effects of the water volume fraction, gas extraction rate, particle mass flow rate, particle size, and bending angle on the erosion location and rate of the pipe columns were investigated. The findings indicate that when the water content volume fraction is low, the water production volume minimally affects the maximum erosion rate of pipe columns. Conversely, the gas extraction rate exerted the most significant influence on the column erosion, showing a power function relationship between the two. When gas extraction volume exceeds 60 × 104 m3/d, the maximum erosion rate surpasses the critical erosion rate of 0.076 mm/a. This coincided with the increased sand mass flow rate, although the maximum erosion rate of the pipe columns remained relatively steady. The salt mass flow rate demonstrated a linear relationship with the erosion rate, with the maximum erosion rate exceeding the critical erosion rate of 0.076 mm/a. The maximum erosion rate of the pipe columns increased, stabilized with larger sand and salt particle sizes, and exhibited an increasing trend with the bending angle. For gas extraction volumes exceeding 46.4 × 104 m3/d and salt mass flow rates exceeding 22 kg/d, the maximum erosion rate of pipe columns exceeds the critical erosion rate of 0.076 mm/a. The conclusions of this study are of some importance for the clarification of the influencing law of pipe column erosion under high temperature and high pressure in gas storage reservoirs and for the formulation of measures for the prevention and control of pipe column erosion in gas storage reservoirs.

Evaluation of future hydropower potential for mountainous headwaters in response to climate change

Snowmelt runoff and hydropower generation performance together with reservoir storages were evaluated for climate projections in two mountainous headwaters in Türkiye’s north (Black Sea Region) and south (Mediterranean Region). The EU-CORDEX database was used to obtain an ensemble of different Global Climate Models under two scenarios. Moreover, evaluations were performed regarding the Global Warming Levels. The results indicate that a dramatic increase in temperatures and alterations in precipitation patterns will bring significant decreases in snow variables and inflows, which will be particularly pronounced in the southern basin. HBV-Light and WEAP model were used to estimate future reservoir inflows and hydropower generation projections through reservoir operations, respectively. The hydropower generation is anticipated to decline up to 35% and 9% in the southern and northern basins, respectively, for far future (2075-2099). Four management scenarios (including increased irrigation and operational hydropower capacity) were assessed for reconsideration of operation strategies.

Building materials could store more than 16 billion tonnes of CO2 annually.

Achieving net-zero greenhouse gas emissions likely entails not only lowering emissions but also deploying carbon dioxide (CO2) removal technologies. We explored the annual potential to store CO2 in building materials. We found that fully replacing conventional building materials with CO2-storing alternatives in new infrastructure could store as much as 16.6 ± 2.8 billion tonnes of CO2 each year-roughly 50% of anthropogenic CO2 emissions in 2021. The total storage potential is far more sensitive to the scale of materials used than the quantity of carbon stored per unit mass of materials. Moreover, the carbon storage reservoir of building materials will grow in proportion to demand for such materials, which could reduce demand for more costly or environmentally risky geological, terrestrial, or ocean storage.

Repurposing depleted unconventional reservoirs for hydrogen storage: Challenges and opportunities

Repurposing depleted unconventional reservoirs for hydrogen storage: Challenges and opportunities

Physiological and behavioral responses of the Baltic clam Macoma balthica to a laboratory simulated CO2-leakage from a subseabed carbon storage site.

Carbon capture and storage in sub-seabed geological reservoirs is now officially included in the atmospheric CO2 emissions reduction policy and meets the agenda of Sustainable Development Goals (SDGs). Over the last few years biological risk assessment studies have delivered substantial empirical data on possible consequences of CO2 leakages from underwater storage sites on benthic systems. Current knowledge on Carbon Capture and Storage CCS associated risks is limited to marine systems. Yet there are multiple areas identified as suitable for carbon storage, but their hydrogeochemical features are so distinct that they should be studied as separate cases. Baltic Sea is one example of an area but is host to a unique - in a world scale - ecosystem with low salinity in combination with reduced oxygen availability in the benthic zone. Geological surveys have designated a potential storage site in the Southern Baltic Sea, namely the B3 oil field. Thus, this study focuses on biological effects of seawater acidification caused by a simulated CO2 leakage scenarios under laboratory conditions on a model macrobenthic in-faunal species. Baltic clams Macoma balthica were exposed to different environmental pH scenarios: pH7.7 (no leakage), pH7.0 (moderate hypercapnia) and pH6.3 (severe hypercapnia) in three independent experiments conducted with the use of a hyperbaric tank (Karl Eric Titank) mimicking hydrostatic pressure of 900kPa, relevant to conditions at the B3 field. Selected physiological aspects of the Baltic clam, such as survival, shell growth rate, morphometric condition and biochemical composition were investigated along with their behavioral responses, i.e. sediment burrowing activity. The results showed modest effects of hypercapnia on physiological performance of the clams that did not lead to greater mortality in neither of the tested leakage scenarios. Apart from high survival of the clams even in the lowest seawater pH (6.3) there were only little changes observed in the burrowing depth of the clams and biochemical composition of their soft tissues related to seawater acidification. The most evident physiological responses of the clams to prolonged hypercapnia (40days at pH6.3) were manifested in decreased shell growth.

CO2 Utilization and Geological Storage in Unconventional Reservoirs After Fracturing

CO2 Utilization and Geological Storage in Unconventional Reservoirs After Fracturing

Subsurface CO2 Storage in Unconventional Reservoirs: Insights into Pore-Scale Characterization of Geochemical Interactions and Particle Migration

Subsurface CO2 Storage in Unconventional Reservoirs: Insights into Pore-Scale Characterization of Geochemical Interactions and Particle Migration

Time dependency of permeability and deformation of coal during gas storage in deep coal reservoirs

Time dependency of permeability and deformation of coal during gas storage in deep coal reservoirs

Development of Performance Index Model for Assessing the Multipurpose Reservoir Storage Capacity

Development of Performance Index Model for Assessing the Multipurpose Reservoir Storage Capacity

Improving Global Reservoir Parameterizations by Incorporating Flood Storage Capacity Data and Satellite Observations

AbstractAccurate reservoir representation in large‐scale river models remains challenging owing to limited access to data on reservoir operations. We contribute to model development by introducing a global machine‐learning based flood storage capacity (FSC) data set and a satellite‐based target storage reservoir operation scheme (SBTS). The FSC data set for 1,178 flood control reservoirs is constructed using multiple reservoir attributes and reported FSC data. Integrating these FSCs into SBTS enables its global applicability with generic formulations of reservoir zoning. Then, we develop SBTS by introducing monthly median values of satellite storage data as target storage parameters. With these seasonal patterns as constrains, improvements in simulation results are achieved. When simulated with observed inflow, SBTS performed significantly better (median Kling‐Gupta efficiency values of 0.52 and 0.17 for outflow and storage simulations among 289 reservoirs), compared to the previous reservoir operation scheme with linearly interpolated target storage parameter (0.41 and −0.19). Compared to two existing global schemes without seasonal target storages, SBTS demonstrates improved performance for many reservoirs whose inflow seasonal pattern is more regular. When coupled with a global river model, it improved discharge simulations across 293 downstream gauges, with overall performance, peak, and low flow improving at 40%, 21%, and 35% of gauges, respectively, compared to simulations without reservoirs. However, reservoir simulations do not improve notably due to the biases in simulated inflow to reservoirs. We demonstrated that machine‐learning FSC and satellite observations help improve reservoir parameterizations, and found that improvements in other aspects of river modeling are essential for accurately reproducing discharge patterns.

Integrated Three-Dimensional Structural and Petrophysical Modeling for Assessment of CO2 Storage Potential in Gas Reservoir

Abstract Carbon dioxide (CO2) storage in oil and gas reservoirs is one of the most effective methods for enhancing hydrocarbon recovery efficiency and mitigating climate change by securely storing CO2. However, building a realistic three-dimensional (3D) geological model for these storage reservoirs poses a significant challenge. To address this, employing a novel methodology combining 3D structural and petrophysical modeling, our study presents a pioneering effort to assess the CO2 storage potential of the faulted reservoir between the G- and E-sands of the Lower Goru Formation in the Kadanwari Gas Field (KGF), Middle Indus Basin (MIB), Pakistan. Analysis of seismic data revealed a complex reservoirs structure affected by normal faults oriented in a northwest–southeast direction. These faults partition the reservoir into several compartments and could serve as potential pathways for CO2 migration. Three-dimensional structural modeling unveiled complex features, for example horsts, grabens, and half-grabens, formed through multiple deformation stages. Petrophysical modeling indicated promising reservoir characteristics, that is high porosity and permeability in the desired zone. Three-dimensional property models were generated using sequential Gaussian simulation to represent the distribution of petrophysical properties, for example porosity, permeability, shale volume, and water saturation. Geological uncertainties were incorporated enabling the calculation of pore volume distribution and corresponding uncertainty. A novel technique was developed to assess the probable CO2 storage potential in the KGF, considering its distinctive features. The study revealed a storage potential ranging from 10.13 million tons (P10) to 101.54 million tons (P90), with an average potential of 53.58 million tons (P50). Our study offers a comprehensive approach to evaluating CO2 storage potential in complex geological zones, filling a knowledge gap in existing literature on carbon neutrality efforts in Pakistan. These findings lay the groundwork for future initiatives in geological CO2 storage in the MIB and support the country’s efforts to reduce carbon emissions.

Evaluation of hydrogen storage in sandstone reservoirs using 1H nuclear magnetic resonance spectroscopy.

Evaluation of the hydrogen storage capacity of porous rocks is crucial for underground hydrogen storage. Using 1H nuclear magnetic resonance (NMR) spectroscopy, we successfully characterized the hydrogen responses and identified storage mechanisms in Berea sandstone under varying water saturation. The results indicate that the injected hydrogen behaves as a free gas phase and is capable of occupying the empty pore volume regardless of the saturation state. No hysteresis was observed during injection and production cycles.

Ensemble-based assisted history matching of DTS monitoring data in HT-ATES systems: application to a real-life case study

Underground heat storage is an important element in accelerating the energy transition. It can significantly contribute to CO2 emission reduction and cost savings since it is one of the cheapest forms of energy storage and it enables the seasonal storage of large energy surpluses from sustainable sources, e.g. wind, sun, geothermal. Numerical models are used for the prediction of thermal behavior important in establishing the high efficiency of the high temperature aquifer thermal energy storage (HT-ATES) systems. However, the lack of exact knowledge of the subsurface conditions introduces modeling uncertainty. It is therefore important to employ approaches that reduce subsurface uncertainty. History matching is a methodology where the numerical models are updated to match historical observations that will in turn not only increase understanding of the subsurface but also improve accuracy of the model predictability of future behavior. In this research, models of the first large-scale operational HT-ATES system in Middenmeer, the Netherlands, were used to evaluate the thermal evolution in the storage aquifer and the over- and underburden clay layers. The HT-ATES system, consisting of a hot and warm well, with a monitoring well inbetween, became operational in the summer of 2021. The extensive monitoring program implemented for the first few operational years provided an opportunity to study the performance of such a system from an environmental and operational point of view. A state-of-the-art assisted history matching approach was applied to the first storage cycle, using a coupling between history matching software and the thermal flow simulator. This approach was compared to a more traditional single-model manual history matching method. Rock properties of the aquifer and over- and underburden layers were updated in the randomly generated prior ensemble of models to fit the simulated temperature evolution measured down the monitoring well with the distributed temperature sensing (DTS) data. The observations gathered during the second year of operations were used to validate the accuracy of the prediction capabilities of the updated models. The obtained results indicate the value of history matching to improve understanding of the subsurface conditions for HT-ATES systems and obtain models with better predictability of the future behavior of heat in the storage reservoir and overburden formations. Such improved models are instrumental in providing engineers with a better quantitative grip on the environmentally responsible storage potential and heat deliverability of the target storage site, which is important to achieve cost-effective site-specific design (e.g. number of wells, well placement) and performing operational strategies (e.g. injection/production rates and temperatures) for new HT-ATES systems. Moreover, the benefits of the assisted history matching approach over manual method are highlighted and both approaches are validated where the assisted history matching method produced more accurate predictions than the manual approach.

Physics-based numerical evaluation of High-Temperature Aquifer Thermal Energy Storage (HT-ATES) in the Upper Jurassic reservoir of the German Molasse Basin

Abstract. Concepts of High-Temperature Aquifer Thermal Energy Storage (HT-ATES) (> 50 °C) are investigated in this study for system application in the Upper Jurassic reservoir (Malm aquifer) of the German Molasse Basin (North Alpine Foreland Basin). The karstified and fractured carbonate rocks exhibit favourable conditions for conventional geothermal exploitation of the hydrothermal resource. Here, we perform a physics-based numerical analysis to further assess the sustainability of HT-ATES development in the Upper Jurassic reservoir. With an estimated heating capacity of approx. 19.5 MW over half a year, our approach aims at determining numerically the efficiency of heat storage under the in situ Upper Jurassic reservoir conditions and projected operation parameters. In addition, the hydraulic performance of the HT-ATES system is further evaluated in terms of productivity and injectivity index. The numerical models build upon datasets from three operating geothermal sites at depths of approx. 2000–3000 m TVD, located in a subset of the reservoir dominated by karst-controlled fluid fluxes. Commonly considered as a single homogeneous unit, the 500 m thick reservoir is subdivided into three discrete layers based on field tests and borehole logs from the three considered sites. The introduced vertical heterogeneity with associated layer-specific enhanced permeabilities allows to examine potentially arising favourable heat transfer, and in combination with the facilitated high operation flow rates (100 kg s−1) to evaluate thermal recoveries in the multilayered reservoir. All simulations account for fluid density and viscosity variation based on thermodynamically consistent equations of state (EOS). Computation results reveal that the reservoir layering induces preferential fluid and heat migration primarily into the high-permeability zone, while thermal front propagation into the lower permeable rock matrix is inhibited. The simulations further display a gradual temperature increase in the warm wellbore and its surrounding host rock, and a consequent progressive improvement in the heat recovery efficiency. Despite the elevated permeability that may trigger advective heat losses, heat recovery factor values range from approx. 0.7 over the first year of operation to over 0.85 after 10 years of operation. An additional scenario is examined with fluid injection solely in the high permeable zone, in order to quantify potential enhancement in the recovery efficiency by omitting fluid injection in the lower-permeability layers where heat propagation is diminished. This is due to the geometrical shape of the thermally perturbed rock volume as heat losses occur during thermal equilibration between injected fluid and reservoir rock, as well as at the contact-surface area between propagating thermal front and adjacent rock matrix. Results suggest that under the stratified reservoir configuration, additionally constrained by the selected spatial distribution of rock properties, heat storage performed only into the upper high-permeability zone corresponds to an improved thermal performance. Simulation results further indicate that density-induced buoyant fluxes, which would considerably decrease thermal efficiencies are inhibited in the system, and the prevailing heat transport mechanism is forced convection.

MASTER RECESSION CURVE VISUALIZATION USING SEVEN BASEFLOW RECESSION MODELS IN PAIRED WATERSHEDS

River flow recession analysis plays a crucial role in understanding how watersheds release water during dry periods. Consequently, modeling baseflow recession is closely related to the characteristics of unconfined aquifers, storage behavior, and the discharge properties of the watershed. While several theories exist on modeling recession curves, limited research has compared different approaches regarding baseflow recession characteristics. This study aims to model seven baseflow recession equations in paired watersheds in Ambon City. The research methodology involves calibrating seven baseflow recession models using the Recession Curve (RC) 4.0 Hydro Office software. The tested models include Linear Reservoir, Exponential Reservoir, Double Exponential Horton, Dupuit-Boussinesq Aquifer Storage, Depression Storage, Turbulent Flow Model, and Hyperbolic Function Model. The calibration results yield optimal combinations of recession parameters. The parameterization order from highest to lowest is as follows: Depression Storage, followed by the Hyperbolic Function, Exponential Reservoir, Turbulent Flow Model, Double Exponential Horton, Linear Reservoir, and Dupuit-Boussinesq Aquifer Storage. Quantifying baseflow recession constants and coefficients is essential for understanding baseflow behavior. Visualizing the slope of the Recession Curve (MRC) reveals that models with high recession constants tend to have gradual MRCs, while low recession constants result in steep MRCs. The MRC slope further describes the relationship between storage conditions and discharge from the watershed. The advantage of creating MRCs from discontinuous recession segments lies in their ability to appropriately describe the MRC process and provide quantitative parameters relevant to drainage mechanisms. MRCs also serve as an optimal automated computational tool.

A New Procedure for Determining Monthly Reservoir Storage Zones to Ensure Reliable Hourly Hydropower Supply

The uncertainty of natural inflows and market behavior challenges ensuring a reliable power balance in hydropower-dominated electricity markets. This study proposes a novel framework integrating hourly load balancing on typical days into a monthly scheduling model solved with Gurobi11.0.1 to evaluate demand-met reliability across storage and inflow states. By employing total storage as a system state to reduce dimensional complexity and simulating future runoff scenarios based on current inflows, the method performs multi-year statistical simulations to assess reliability over the following year. Applied to a system of 39 hydropower reservoirs in China, the case studies of present models and procedures suggest: (1) controlling reservoir storage levels during the dry season is crucial for ensuring the power demand-met rate in the following year, with May being the most critical month; (2) the power demand-met rate does not monotonically increase with higher storage levels—there is an optimal storage level that maximizes the demand-met rate; and (3) June and October offer the greatest flexibility in storage adjustment to achieve the highest demand-met reliability.

Integrated management of lakes, reservoirs, and their basins is critical for a climate-resilient planet: an urgent wake-up call from collective amnesia

ABSTRACT Integrated management of lakes and reservoirs and their basins is vital for preserving their significant socioeconomic and ecological benefits, which are essential for climate resilience. Lakes and reservoirs store 88% of the Earth's fresh surface water, providing water, food, energy security, flood protection, drought mitigation, and ecosystem services. This article highlights the rapid depletion and deterioration of these Lentic (standing) waters and the consequent loss of valuable benefits, threatening the global water supply and exacerbating environmental and climate crises. It discusses the evolution of lake management practices and contrasts these with strategies for managing lotic (flowing) waters. It summarizes collaborative best practices for Lake Basin Governance developed through a multiagency partnership. It reviews recent global initiatives to sustainably manage lakes, integrate storage, address aging dams, and foster partnerships and cooperation. It highlights the widespread failures across international water and environmental policies and institutions. The article calls on the global water and environmental community to awaken from collective amnesia, act, and implement best practices for governing lakes, reservoirs, and basins. Our companion article examines the institutional inertia hindering integrated action and offers collaborative opportunities for integrating land and water management in lake and reservoir basins to enhance climate resilience.

Quantifying the value of stakeholder-elicited information in models of coupled human–water systems

Causal loop diagrams (CLDs) based on expert or stakeholder inputs inform the structure of socio-hydrological models (SHMs). Here, we explore the sensitivity of SHMs, a category of system dynamic models that simulate human-water feedback to varying degrees of stakeholder inputs. We develop three alternative CLDs to understand the dynamics of a large multi-purpose reservoir in southern India. CLD1 is a conventional water balance-based reservoir model that simulates surface water availability in the region. CLD2 incorporates reservoir operator’s judgement and groundwater pumping. CLD3 further incorporates adaptive behavior of water users by adjusting demands in response to droughts. CLD2 and CLD3 were developed via semi-structured interviews. SHM outputs were validated via reservoir storage, groundwater levels in the command area, and ratio of surface to groundwater for farming during 2000-2013. SHM3 outperformed SHM1 and SHM2, especially in post drought period, highlighting the importance of testing different SHMs structures to better understand human-water interactions under extreme conditions.