As industry moves from fossil fuels to green energy, substituting hydrocarbons with hydrogen as an energy carrier seems promising. Hydrogen can be stored in salt caverns, depleted hydrocarbon fields, and saline aquifers. Among other criteria, these storage solutions must ensure storage safety and prevent leakage. The ability of a caprock to prevent fluid from flowing out of the reservoir is, thus, of utmost importance. In this review, the main factors influencing fluid flow are examined. These are the wettability of the caprock formation, the interfacial tension (IFT) between the rock and the gas or liquid phases, and the ability of gases to diffuse through it. To achieve effective sealing, the caprock formation should possess low porosity, a disconnected or highly complicated pore system, low permeability, and remain strongly water-wet regardless of pressure and temperature conditions. In addition, it must exhibit low rock–liquid IFT, while presenting high rock–gas and liquid–gas IFT. Finally, the effective diffusion coefficient should be the lowest possible. Among all of the currently reviewed formations and minerals, the evaporites, low-organic-content shales, mudstones, muscovite, clays, and anhydrite have been identified as highly effective caprocks, offering excellent sealing capabilities and preventing hydrogen leakages.

Reservoir permeability reflects the pore structure and fluid flow capacity of subsurface formations, serving as a critical parameter in hydrocarbon reserve evaluation and field development decision making. This study constructs a multisource multimodal data set that integrates acoustic, resistivity, and radioactive logging data, interpreted logs, nuclear magnetic resonance (NMR) T2 spectra, and geological stratification text. To accurately predict permeability from such heterogeneous inputs, we propose an Explicit Tensor Interaction Network (ETIN) that integrates long short-term memory (LSTM), convolutional neural network (CNN), and deep neural network (DNN) modules to extract modality-specific features from time series, two-dimensional (2D) images, and structured textual inputs, respectively. The tensor interaction layer in ETIN explicitly preserves original modality representations. It constructs binary interaction planes and a ternary interaction core, achieving joint modeling of intra-modal semantics and high-order inter-modal interactions. Comparative experiments using field data from 10 wells in the Jiyuan area of the Ordos Basin, China, demonstrate that ETIN significantly outperforms early fusion (EF), bilinear pooling network (BPN), and the traditional Schlumberger-Doll Research (SDR) model, achieving a coefficient of determination (R2) of 94.95% and a root mean square error (RMSE) of 0.3168, particularly excelling in low- to ultralow-permeability reservoirs. Further analysis reveals that the NMR T2 spectrum contributes the most to permeability prediction among all modalities and that cross-modal interaction alone is insufficient to achieve optimal performance. Fusion models can reach peak accuracy only by jointly preserving key physical modality semantics and introducing high-order interactions. Although geological stratification text carries limited predictive value when used alone, it serves as a strong structural prior during tensor interaction, improving stratigraphic recognition and generalization under complex geological conditions.

In order to correctly model the fluid phase behavior and accurately account for phase compositions, fractions and properties in the reservoir during the hydrocarbon field development, it is necessary in some cases to use nonequilibrium phase behavior models.The signs of non-equilibrium phase behavior of hydrocarbons observed during field development may be associated with various factors. It has been experimentally shown that the so-called “thermodynamic non-equilibrium” behavior (when the phase transition cannot be considered instantaneous compared to the characteristic rate of change of the system state parameters) manifests itself due to the limited specific area of the phase interface. “Hydrodynamic non-equilibrium” behavior (the difference in actual fractions of the produced phases from the expected ones) is observed at high production rates for the reason that one of the phases does not have enough time to segregate and is transported as an aerosol in the second phase, without forming a separate continuous medium. Proper identification of the type of nonequilibrium behavior is a key factor in choosing the correct model.The paper considers specifics of various models to account for non-equilibrium phase behavior. Examples of their practical application are analyzed for various manifestations of non-equilibrium phase behavior and different causes of its occurrence. The problem of modeling fluid flow with nonequilibrium phase transitions is discussed.

To support the European Green Deal and accelerate climate mitigation, the CCUS ZEN project conducted a high-level technical screening of Carbon Capture, Utilization, and Storage (CCUS) value chains in the Baltic and Mediterranean regions. These regions were chosen, since they have lower maturity levels for CCUS compared with the current development in the North Sea region. The study mapped industrial carbon dioxide (CO2) emission sources, potential storage sites, transport infrastructure, and utilization options. Emission clusters and hubs were identified based on volume, location, and industry type, while for each mapped storage site, information was gathered about the type of reservoir (deep saline aquifer or depleted hydrocarbon field), the onshore or offshore location, the capacity of the reservoir and the Storage Readiness Level, indicating the maturity of the capacity evaluation. Transport options included pipelines, shipping, and multimodal solutions were presented. This study defined unique high-level technical CCUS value chain screening workflow for mapping of emitters, infrastructures to storage screening. An open geographical information system was used for mapping the emitters and storage sites from previous reports, and to illustrate emission clusters and possible transport routes, both existing and future infrastructures. The screening revealed significant CO2 emission sources and storage capacities across the regions, with notable clusters in Poland, Germany, Italy, and Turkey. The Baltic region showed three times the storage capacity of the Mediterranean region. Eight promising CCUS value chains were defined, integrating source-sink matching and infrastructure feasibility. A detailed case study of Southern Italy and Greece was presented, to demonstrate the potential for regional CCUS deployment, highlighting challenges such as data availability, storage capacity uncertainty, transport possibilities and stakeholder coordination. This study will provide a foundation for further development and stakeholder engagement in CCUS planning across Europe.

Seismic waves from large earthquakes are known to trigger slip on distant faults, but the underlying mechanisms remain unclear. Using interferometric synthetic aperture radar and local geodetic and seismic data, we show that the 1000-kilometer-distant, February 2023 Kahramanmaraş earthquakes in southeastern Türkiye triggered deformation and/or eruption at 56 mud volcanoes and centimeter-scale aseismic slip on seven faults over tens of kilometers within the fluid-rich Kura Basin in the West Caspian region. This transient deformation event, with an equivalent moment magnitude of 6.1, was coupled with local inflation below major hydrocarbon fields. We postulate that seismic waves led to a change in pore pressure at depth, which in turn triggered aseismic slip along several crustal faults crossing the basin and its surroundings.

The present article is devoted to the study of the distribution of natural radionuclides (238U, 234U, 226Ra, 228Ra, 40K, 210Pb) and oil products in river bottom sediments of the Pechora basin of the Timan-Pechora oil and gas province (north-west Russia). In addition, an analysis of radiological hazard indices for human health is also provided. The region's distinctive geology is characterised by a high concentration of oil and gas fields, the development of which has been linked to environmental concerns, including pollution. To date, the onshore part of the province has seen the discovery of over 268 hydrocarbon fields, of which more than 200 are oil fields. It is evident that the Kolva River (Komi Republic) is one of the most polluted rivers in the province. In order to identify the sources and regularities of radionuclide accumulation in bottom sediments, the total alpha- and beta-radiation activities, the content of organic matter and carbonates, as well as the granulometric composition of sediments were additionally evaluated. The study revealed that the highest activities of natural radionuclides are observed in the bottom sediments of the Kolva River. The activity of 226Ra in the bottom sediments of the Kolva River at certain points has been found to reach 89.0 ± 7.1Bqkg-1. This is generally higher than the activity levels recorded in the bottom sediments of rivers in North-West Russia. Correlation analysis and calculation of 226Ra/228Ra and 226Ra/210Pb isotope ratios demonstrated that relatively high values of 226Ra activity in the bottom sediments of the Kolva River can be associated with oil and gas activity in the region. The following factors are of particular significance in this regard: the low (at the background level) uranium isotope content in bottom sediments, the increased content of oil products (up to 101.2mgkg-1), and the very close correlation of 226Ra with the content of oil products in bottom sediments (R = 0.74). It is important to note that the elevated 226Ra activities detected in the sediments of the Kolva River may have a significant impact on the radioactive composition of the sediments of the Pechora River. Slightly elevated 226Ra activities have been detected in some samples from the Pechora River when compared to clark values and other rivers in the region. The identification of zones exhibiting elevated concentrations of natural radionuclides in the bottom sediments of the Pechora basin has informed an assessment of their radiation safety parameters, with particular regard to their potential impact on human health. The findings of the study indicated that the radioecological situation within the Pechora basin remains stable and at a safe level at present. However, the authors note the necessity of periodic radioecological monitoring on the territory of the Timan-Pechora province for the timely detection of contamination of environmental objects with natural radionuclides.

Наблюдающаяся в последние годы тенденция увеличения темпов падения базовой добычи нефти несет риски невыполнения планов и недостижения проектных коэффициентов извлечения нефти (КИН) на многих месторождениях углеводородов. В складывающихся условиях исключительно актуальным является применение физико-химических методов увеличения нефтеотдачи (ФХ МУН), в частности, составов потокорегулирующего действия. Отечественный опыт показывает, что из числа таких методов наиболее эффективными являются технологии выравнивания профиля приёмистости (ВПП) нагнетательных скважин и потокоотклоняющие технологии (ПОТ) с применением различных дисперсно-содержащих составов. Настоящая работа посвящена изучению возможности применения гидрофобизированного наполнителя в дисперсносодержащих системах. Показаны преимущества использования такого наполнителя перед промышленно применяемыми в настоящее время – глинопорошок, древесная мука. An increasing trend in the oil production decline rate observed over the last few years poses risks of failure to meet production targets and to achieve planned oil recovery efficiency in many hydrocarbon fields. Under current conditions, use of physical-and-chemical EOR methods, particularly, flow diverting agents, is of utmost importance. Domestic experience shows that the most efficient among such EOR methods are conformance control in injection wells and flow diverting technologies using various disperse systems. The paper studies the applicability of a water-repellent filling agent in disperse systems. The authors present the advantages of using this agent compared to the currently applied industrial fillers, such as mud powder and wood flour.

Relevance. This paper discusses the optimization of multi-reservoir field development at the Uzen oilfield using geochemistry and an innovative method for inflow distribution across productive layers. Aim. To minimize the negative impact of reservoir property heterogeneity in hydrocarbon fields, a comprehensive approach is proposed. It includes geochemical analysis of oil and the development of specialized downhole equipment for oil-water separation. This approach is aimed at reducing capital investments and operational costs, improving production control, and enhancing the economic efficiency of field development. Methods. The application of downhole injection and separation systems equipped with electrically driven centrifugal pumps opens new opportunities for the oil production sector. This technology significantly increases the efficiency and cost-effectiveness of oil extraction by boosting oil flow rates from existing production wells through the inclusion of new reservoir intervals and reducing lifting and pumping costs via in-well separation and simultaneous water reinjection into the formation. Even without a complete economic analysis, the advantages of implementing this new method in the Parsumurun Dome of the Uzen field are evident, promising significant benefits compared to traditional approaches. Reduced operating expenses and capital investments, combined with the potential for increased oil production revenues, ensure high economic efficiency for the proposed solutions. These factors make investment in this method particularly attractive, offering substantial improvements in the financial performance of field development. Results and conclusions. Pilot testing at the Parsumurun Dome, which contains only 2% of the Uzen field geological oil reserves, provides a unique opportunity to evaluate the effectiveness of the proposed method. Positive results from the pilot trials could justify full-scale implementation across the entire field, offering considerable technological and economic benefits.

Purpose. To improve the accuracy of lithotype classification and reduce uncertainty in hydrocarbon prospecting predictions under conditions of weak contrast in the elastic properties of reservoirs and the surrounding rock by testing a probabilistic approach to seismic data interpretation. Methodology. The study applies a technological approach that includes: 1. Constructing probability distribution functions for lithotypes based on lithological trend data from wells. 2. Using inversion to create cubes of elastic properties and their further analysis using Bayes’ principle. 3. Lithotype classification based on the probabilistic approach by aligning inversion data with probability distributions. Findings. High-resolution seismic data processing was carried out successfully, which ensured their high resolution. Elastic property volumes were obtained and used to assess the probability of various lithotypes. The Bayesian approach to lithotype classification was implemented, demonstrating improved interpretation accuracy in conditions of low elastic property contrast. Promising structures were identified, confirming the effectiveness of the proposed approach in complex geological settings. Originality. A probabilistic method for seismic data analysis was tested, based on the integration of probability distribution functions and inversion data. This methodology allows for accounting for lithological variability and uncertainties during interpretation, representing a novel approach for conditions of low elastic property contrast. Practical value. The developed methodology can be applied in hydrocarbon exploration and field development when reservoir and host rock physical properties exhibit weak contrast. It helps reduce geological risks, optimize drilling site selection, and enhance the economic efficiency of geological exploration.

In recent years, major breakthroughs have been achieved in oil and gas exploration within China’s complex thrust–fault zones in the western region, confirming their significant potential. The northern piedmont zone of the Turpan–Hami Basin, a classic thrust–fold belt formed by the Bogda Orogenic belt’s overthrusting, has seen the discovery of several Jurassic–Cretaceous hydrocarbon fields, yet exploration at its thrust-front margins remains relatively underdeveloped. This study focuses on the central piedmont segment at Qialekan and Kekeya, integrating 3D seismic data with fault-related folding theory and balanced cross-section restoration to systematically analyze the area’s tectonic evolution. We specifically examine the formation and modification of wedge structures and assess their petroleum geological significance. Our results indicate that the wedge bodies formed in the Late Jurassic, along with their subsequent basinward insertion, critically controlled the present-day structural framework. In the Qialekan area, wedge formation coincided with the main hydrocarbon expulsion phase of underlying Permian source rocks. Type I faults acted as effective migration pathways, while later tectonic reworking was limited, favoring for hydrocarbon preservation. In contrast, in the Kekeya area, wedge structures underwent intense modification by Type II faults, which pierced the wedge and facilitated vertical hydrocarbon migration, creating a mixed-source accumulation pattern. The findings of this study provide new theoretical insights and practical guidance for future exploration in the northern piedmont zone and also offer a valuable reference for hydrocarbon exploration in structurally similar foreland basins.

Geoscience Visual Presentation G02 The influence of 4D geomechanics extends to various hydrocarbon field activities, encompassing exploration, development and hydrogen storage in depleted reservoirs. Its significance becomes more pronounced when dealing with challenging and depleted environments during injection. This paper outlines the utilisation of 4D geomechanics modelling in the hydrogen storage in depleted reservoirs. The application involves employing 4D geomechanics to comprehend subsurface dynamics and strategically plan wells in intricate environments. This method integrates the fourth dimension, time, into conventional 4D geomechanical models. It involves estimating the unconfined compressive strength, which is a key parameter in assessing the material’s resistance to axial stress without lateral support. In situ stresses were calculated using poroelastic equations. 4D coupled simulation has been created using finite element method. The primary aim is to assess the stability of the formation and seal integrity. This model has improved the analysis of bedding plane failures by simulating the current stress profile. Consequently, future storage and production scenarios can plan securely, minimising reservoir damage and avoiding significant fault reactivation issues. To access the Visual Presentation click on the link on the right. To read the full paper click here

Ogbo Field, one of the prolific hydrocarbon field in the Niger Delta basin was studied for the purpose of delineation of the environment of deposition of sediments and reconstruction of sequence stratigraphic framework within the field. Methodology employed in this study include well logs and biostratigraphic analyses. Two major lithologies were identified in the field and consist of sandstone and shale. Sediment depositional environments varied from marginal marine (deltaic) to shallow marine. Five depositional sequences (SEQ.1, SEQ.2, SEQ.3, SEQ.4 and SEQ.5) bounded by five sequence boundaries (SB) and six maximum flooding surfaces (MFS) were identified in the sequences. The SBs dated 13.1Ma, 12.1Ma, 10.6Ma, 10.35Ma and 8.5Ma while the MFSs dated 15Ma, 12.8Ma, 11.5Ma, 10.4Ma, 9.5Ma and 7.4 Ma. The sequences were grouped into highstand system tracts (HST), transgressive system tracts (HST) and lowstand system tracts (LST), indicating aggrading, retrograding and prograding stratal stacking patterns respectively. The sandy unit was characterized by TST while HST dominated the shale zone.

This study explores the use of satellite gravity data and derived crustal models for predicting oil and gas potential in the east of the Russian platform. The research utilizes structural data (including GOCE satellite gravity-derived Moho depth), thermal data, and hydrocarbon potential data. The methodology involves three steps: 1) statistical analysis using Student's -test to identify significant parameters distinguishing areas with and without hydrocarbon fields; 2) classification of the study area into three zones based on their hydrocarbon potential; and 3) application of a logistic regression machine learning model to forecast hydrocarbon potential in uncertain areas. The results show that most analyzed parameters have statistically significant differences between areas with and without hydrocarbon fields. The logistic regression model achieves 83% accuracy in predicting hydrocarbon potential. The study concludes that satellite gravity data and derived crustal models can be effectively used to forecast oil and gas potential in sedimentary basins, with the Precaspian basin, Cis-Ural trough, parts of the Central-Russia and Mezen rift systems, and the Timan-Pechora basin identified as the most promising areas in the east of the Russian platform.

In this article, we consider the roles of transcrustal magma- and fluid-conducting faults (TCMFCFs) in the formation of mineral deposits, showing the importance of deep sources of heat and hydrothermal solutions in the genesis and history of deposit formation. As a result of the impact on the lithosphere of mantle plumes rising along TCMFCFs, intense block deformations and tectonic movements are generated; rift systems, and volcanic–plutonic belts spatially combined with them, are formed; and intrusive bodies are introduced. These processes cause epithermal ore formation as a consequence of the impact of mantle plumes rising along TCMFCF to the lithosphere. At hydrocarbon fields, they play extremely important roles in conductive and convective heat, as well as in mass transfer to the area of hydrocarbon generation, determining the relationship between the processes of lithogenesis and tectogenesis, and activating the generation of hydrocarbons from oil and gas source rock. Detection of TCMFCFs was carried out using MMSS (the method of microseismic sounding) and MTSM (the magnetotelluric sounding method), in combination with other geological and geophysical data. Practical examples are provided for mineral deposits where subvertical transcrustal columns of increased permeability, traced to considerable depths, have been found; the nature of these unique structures is related to faults of pre-Paleozoic emplacement, which determined the fragmentation of the sub-crystalline structure of the Earth and later, while developing, inherited the conditions of volumetric fluid dynamics, where the residual forms of functioning of fluid-conducting thermohydrocolumns are granitoid batholiths and other magmatic bodies. Experimental modeling of deep processes allowed us to identify the quantum character of crystal structure interactions of minerals with “inert” gases under elevated thermobaric conditions. The roles of helium, nitrogen, and hydrogen in changing the physical properties of rocks, in accordance with their intrastructural diffusion, has been clarified; as a result of low-energy impact, stress fields are formed in the solid rock skeleton, the structures and textures of rocks are rearranged, and general porosity develops. As the pressure increases, energetic interactions intensify, leading to deformations, phase transitions, and the formation of chemical bonds under the conditions of an unstable geological environment, instability which grows with increasing gas saturation, pressure, and temperature. The processes of heat and mass transfer through TCMFCFs to the Earth’s surface occur in stages, accompanied by a release of energy that can manifest as explosions on the surface, in coal and ore mines, and during earthquakes and volcanic eruptions.

The influence of 4D geomechanics extends to various hydrocarbon field activities, encompassing exploration, development and hydrogen storage in depleted reservoirs. Its significance becomes more pronounced when dealing with challenging and depleted environments during injection. This paper outlines the utilisation of 4D geomechanics modelling in the hydrogen storage in depleted reservoirs. The application involves employing 4D geomechanics to comprehend subsurface dynamics and strategically plan wells in intricate environments. This method integrates the fourth dimension, time, into conventional 4D geomechanical models. It involves estimating the unconfined compressive strength, which is a key parameter in assessing the material’s resistance to axial stress without lateral support. In situ stresses were calculated using poroelastic equations. 4D coupled simulation has been created using finite element method. The primary aim is to assess the stability of the formation and seal integrity. This model has improved the analysis of bedding plane failures by simulating the current stress profile. Consequently, future storage and production scenarios can plan securely, minimising reservoir damage and avoiding significant fault reactivation issues.

4D SEISMIC IN RUSSIA: EXPERIENCE, PROBLEMS AND PROSPECTS

Ogbo field, one of the prolific hydrocarbon field in Niger Delta basin has been studied holistically using integrated geological and geophysical approach. The study integrates well log, seismic and biostratigraphic data to reconstruct and re-evaluate a comprehensive sequence stratigraphic framework within the field. In this study, two major lithologies were identified which are shale colour coded with black and sandstone color coded with yellow. Well logs were correlated with siesmic data in other to generate synthetic traces. Also, five depositional sequence boundries (SEQ.1, SEQ.2, SEQ.3, SEQ.4 and SEQ.5) were identified with maximum flooding surface demarcating each sequence which also was grouped into parasequences of highstand system tracts, transgressive system tracts and lowstand system tracts. The bounded sequences revealed a prograding, retrograding and aggrading character. The sand unit was characterized by TST while HST dominate shale zone. Also, the structural interpretation of seismic data shows the presence of fault which indicate hydrocarbon trap in flat spot, dim spot stands out and bright spot which is the AM prospect. The sequence stratigraphy of Ogbo field demonstrates that it’s still a producing well but drilling activities should focus on the bright spot within the faults for commercial exploitation of hydrocarbon in the field.

The paper addresses a range of issues related to the development of mathematical models for a Digital Twin of an oil and gas production company, aimed at managing technological processes at its gas field facilities within the framework of the fourth industrial revolution, based on the Industry 4.0 concept.Considering the specific characteristics of gas field facilities, the primary purpose of the Digital Twin from the perspective of technological process management is formulated. The most preferred tool — predictive analytics—is presented for data analysis and interpretation, enabling the forecasting of parameters for technological processes occurring at gas field facilities.A six-layer structure of the Digital Twin is proposed, including: regulatory and reference information, electronic design and estimate documentation, a graphical representation layer of objects, engineering data, mathematical models, and real-time data obtained from information management systems and automated process control systems integrated with telemetry systems that manage the operation of production wells.A structural diagram of the management system for an oil and gas production company is presented. The applicability of known modeling methods for describing technological processes at gas field facilities is analyzed, and the choice of modeling methods for each management level is justified, taking into account the purpose and technological characteristics of the facility.It is demonstrated that this modeling ideology, applied in practice, has led and continues to lead to the development of specific technical and technological solutions for managing technological processes at various stages and modes of hydrocarbon field development, protected by Russian invention patents.The proposed ideas and solutions for creating the Digital Twin serve as a foundation for defining requirements for the development and implementation of design solutions for information management systems. These systems ensure the most efficient management of technological processes across all aspects of the integrated operations of oil and gas production companies.

Central North Sea Eocene/Palaeocene and Late Cretaceous (P/C) reservoirs host high relief hydrocarbon fields flanking piercing salt diapirs and lower relief fields where un-pierced. This study aimed to predict the un-imaged trap relief on a steep diapir flank–the Isolde prospect–identified on poor seismic data. Analogous CNS diapirs have 2D limb lengths consistent with P/C strata being perched roof flaps; formerly contiguous roof strata prior to piercement marked by Eocene apparent onlaps. Consequently, top Palaeocene relief varies with regional distance across the trap, enabling calibrated prediction of c. 900m of un-imaged relief up-dip of the shallowest well on structure, largely confirmed by subsequent 3D reprocessing. A late-stage evolutionary understanding reflecting common characteristics of better-imaged diapirs supports the perched flap model. Limited evidence of Cenozoic salt withdrawal and indications of regionally synchronous structural events reflect episodic, minor active contraction of welded diapirs, driven by fluctuating far-field stresses rather than by halokinesis or substantial contraction. Hydrocarbon fill patterns and in-situ stress data illuminate controls on hydrocarbon phase and column height, with high trap relief favouring large oil columns. Limited borehole breakout data indicates radial minimum horizontal stress, unlike common near-diapir stress assumptions, with implications for drilling, production and storage.

Abstract Direct extraction of lithium from oil field brines, herein referred to as “sedimentary basin lithium brines,” is emerging as an economical and environmentally responsible alternative to hard-rock and salar-style brine resources. Relative to the major lithium chemical-producing countries, North America has scarce traditional lithium ore deposits. Sedimentary basin lithium brines present a promising and readily available domestic supply of lithium. Elevated lithium concentrations (>50 mg/L) are known in hydrocarbon fields across North America, but the origin of these brines, the lithium sources, and lithium enrichment mechanisms are largely debated or unknown. Using the Upper Devonian Leduc Formation (Alberta basin, Canada) as a case study, we document the complexity of unraveling brine genesis and evolution. Competing hypotheses regarding Leduc brine origin, postformational brine modification, and lithium sources confound an understanding of the lithium resource homogeneity and longevity. Using brine-dissolved species and isotopic data, we show that the Leduc brines are regionally geochemically distinct across the Devonian Leduc Formation reef complexes. We conclude that these brines originate from both evaporatively concentrated seawater and the dissolution of evaporite sequences and were subsequently modified by local mixing, diagenesis, and rock-water interaction processes. This compositional heterogeneity has implications for lithium resource exploration, production, and valuation of the Leduc Formation and other sedimentary basin lithium brine resources.