Energy & Fuels最新文献

{"title":"Lithological Control of Gas Hydrate Saturation Determined by Pressure Core Analysis in Subpermafrost Reservoirs of the Alaska North Slope (HYDRATE-02 Geo Data Well)","authors":"Stephen C. Phillips,&nbsp;William F. Waite,&nbsp;Jun Yoneda,&nbsp;Seth S. Haines,&nbsp;Akihiro Hiruta,&nbsp;Melanie E. Holland,&nbsp;Peter J. Schultheiss,&nbsp;Timothy S. Collett","doi":"10.1021/acs.energyfuels.5c04960","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.5c04960","url":null,"abstract":"<p>Quantitatively degassingpressure cores by controlled depressurizationis a key approach to characterizing gas hydrate reservoirs by measuringthe gas hydrate saturation (S_h) of sediments. We measuredS_h for 53 core sections from the Alaska North Slope duringthe JOGMEC-DOE-USGS Collaborative Gas Hydrate R&amp;D Project in Alaska,from subpermafrost sediments that were later subjected to an extended-durationgas production test. We characterized lithologic influences on S_h using physical property core scans (P-wave velocity, gammaray attenuation density, and X-ray computed tomography) and grainsize measurements. Pressure cores were recovered from the Hydrate-02Geo Data Well (GDW) at the Kuparuk State 7-11-12 site through twohydrate-bearing sand reservoirs, the B1 and D1 sands, and their finer-grainedbounding sediments. S_h reaches very high values (68 to91% of the pore space) in silty fine sands within the B1 sand, whichalso contains two lower P-wave velocity intervals (one measured at30% S_h) within the main reservoir. S_h and grainsizes of the B1 sand are generally higher than the D1 sand, whichhosts high S_h (53 to 73%) within its sandy silt to siltyfine sands. The heterogeneous silty clay to silt “seal”sediments directly overlying both reservoirs have low S_h (0 to 13%) even in thin, coarser beds, suggesting minimal methanetransport between the reservoir and seal. S_h decreaseswith depth downward toward the base of both the D1 and B1 sands, correspondingto decreasing grain size. These transitions are underlain by siltyclay to clayey silt sediments with low S_h (&lt;10%), similarto the seal sediments. Slow depressurization was used to estimatea brackish salinity based on the pressure and temperature of the onsetof hydrate dissociation for two core sections within the B1 sand.We show that S_h increases with median grain size, sandcontent, and porosity but exhibits some variation within the sandbeds that is not directly explained by lithology.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21224–21240"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subsurface Microbial Gas Formation in Geoenergy Systems: A Review of Mechanisms, Applications, and Future Perspectives","authors":"Milad Khashay,&nbsp;Alireza Ramandi,&nbsp;Ehsan Esmaeilnezhad","doi":"10.1021/acs.energyfuels.6c04331","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c04331","url":null,"abstract":"<p>Microbial gas formation in subsurfaceenvironments governsthegeneration, transformation, and fate of methane (CH₄),carbon dioxide (CO₂), hydrogen (H₂), and nitrogen(N₂), with direct implications for geoenergy systems. Thisreview integrates the metabolic pathways and reservoir-scale processesthat govern microbial gas formation, including fermentation, methanogenesis,syntrophic interspecies electron transfer, denitrification, and mineral-mediatedreactions. The main novelty of this review is its mechanistic-to-fieldperspective, linking microbial metabolism to gas-fluid behavior, oilrecovery mechanisms, underground H₂ storage (UHS) risks,carbon capture utilization and storage (CCUS) opportunities, and depletedreservoir reuse. For enhanced oil recovery (EOR), in situ microbialgases can support reservoir repressurization, oil swelling, viscosityreduction, and improved sweep efficiency, especially when combinedwith biosurfactants, acids, and biomass. In UHS, microbial activitycan deplete stored H₂, produce CH₄ or H₂S, affect gas purity, and alter permeability via biofilm growth.Microbial CO₂ conversion and depleted reservoirs offeropportunities for integrated gas production and carbon managementin the CCUS. Still, the performance remains constrained by reservoirheterogeneity, microbial kinetics, pressure, salinity, and nutrientdelivery. The review identifies key knowledge gaps and future needs,including high-pressure experiments, real-time microbial monitoring,isotope tracing, and coupled bioreactive transport modeling. Theseadvances are essential for predicting, controlling, and engineeringmicrobial gas processes in low-carbon, subsurface energy systems.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21083–21114"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reservoir Heterogeneity Controls Long-Term CO2 Mineral Trapping and Self-Sealing in Deep Saline Aquifers: Insights from Reactive Transport Simulations","authors":"Fathi Khaleel Saleh Abdul Wahab,&nbsp;Suresh Kumar Govindarajan","doi":"10.1021/acs.energyfuels.6c03981","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c03981","url":null,"abstract":"<p>Geologicalcarbon sequestration in deep saline aquifersis consideredone of the most promising strategies for mitigating anthropogenicCO₂ emissions; however, the influence of reservoir-scaleheterogeneity on long-term trapping efficiency and storage permanenceremains insufficiently quantified. Previous investigations have predominantlyfocused on short-term plume evolution, whereas the coupled impactsof permeability architecture, geochemical reactions, and petrophysicalevolution over geological time scales remain poorly understood. Thisstudy systematically investigates the role of permeability heterogeneityon CO₂ trapping mechanisms using fully coupled multiphasereactive transport simulations performed with CMG-GEM. Five syntheticsaline aquifer models characterized by Lorenz coefficients rangingfrom 0.0 to 0.8 were constructed while maintaining an identical averagepermeability (100 mD) and porosity (0.20). A total of 30 Mt of CO₂ was injected over 30 years, followed by a 970 year postinjectionmonitoring period. Results demonstrate a strong monotonic relationshipbetween heterogeneity intensity and long-term mineralization efficiency.The mineral trapping fraction increased from 32.6% in the homogeneouscase to 83.1% in the highly heterogeneous system, corresponding toa 2.55-fold enhancement after 1000 years. Three distinct mineralizationstages were identified, including an initial lag phase (0–100years), an accelerated precipitation regime (100–600 years),and a stabilization period beyond 600 years. Increasing heterogeneityalso promoted higher pressure buildup, greater porosity reduction,and substantial permeability degradation caused by localized carbonateprecipitation within preferential flow pathways. These findings revealthat reservoir heterogeneity acts as a geochemical amplifier thatenhances fluid–rock interactions and promotes progressive self-sealingbehavior. The Lorenz coefficient provides a practical metric for evaluatingstorage security, predicting long-term mineralization potential, andsupporting comparative assessment of geological carbon storage sites.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21404–21427"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supercritical CO2–Brine–Shale Interaction under Contrasting Depressurization Protocols: Pore-Structure and Micromechanical Responses","authors":"Yiyuan Guo,&nbsp;Zhiping Li,&nbsp;Fan Yang,&nbsp;Xinshu Huang","doi":"10.1021/acs.energyfuels.6c02862","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c02862","url":null,"abstract":"<p>Supercritical CO₂ (ScCO₂) huff-n-puffcanenhance shale oil mobility and support CO₂ utilizationand storage, yet conventional static-soaking tests do not capturetransient pressure drawdown. We compared ScCO₂–brine–shaleinteraction at 60 °C and 15 MPa under two laboratory protocols.The staged dynamic protocol included depressurization, reactor opening,characterization, and repressurization at 3, 7, and 15 d; the static15 d protocol used uninterrupted exposure followed by one slow terminaldepressurization. The staged sequence combines pressure release andCO₂ exsolution/redissolution with repeated cycling andsample handling, so the two complete operating histories form thebasis of comparison. Scanning electron microscopy with energy-dispersivespectroscopy (SEM-EDS) and X-ray diffraction (XRD) characterize localnormalized elemental fractions and fitted relative crystalline-phaseproportions; low-field nuclear magnetic resonance (NMR) and N₂ adsorption characterize pore-fluid relaxation and adsorption-accessiblepore structure; contact-angle and nanoindentation measurements quantifywettability and local micromechanical response. After 15 d under thestaged protocol, the N₂ desorption pore volume is 0.0113cm³/g compared with 0.0092 cm³/g for the Initialaliquot, while the NMR spectrum retains an extension toward longer <em>T</em>₂ relative to the initial state. The water contactangle decreases to 15.85°, and the mean reduced modulus acrossall 36 indentations decreases by 32.5%, including a 14.27 GPa decreasefrom 7 to 15 d. In the present experiments, measurements obtainedunder the staged sequence showed larger baseline-referenced end pointchanges in adsorption-accessible pore volume, water wettability, andlocal reduced modulus than measurements obtained under the static15 d protocol. Together, the study provides a multi-domain descriptivecomparison of the two complete operating histories; beyond this endpoint contrast, the staged intermediate measurements provide a time-resolvedcross-domain record of the tested responses. Independent specimen-levelreplication is required to establish general protocol effects.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21297–21310"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alaska North Slope HYDRATE 02 Geo Data Well Multicomponent Inversion and NMR Log and Core Analysis of the B1 Sand Gas Hydrate Reservoir","authors":"Timothy S. Collett,&nbsp;Niranjan Aryal,&nbsp;Seth S. Haines,&nbsp;Sukru Merey,&nbsp;William F. Waite,&nbsp;Stephen C. Phillips,&nbsp;Margarita V. Zyrianova,&nbsp;Ray Boswell,&nbsp;Than Tin Aung,&nbsp;Jun Yoneda,&nbsp;Machiko Tamaki,&nbsp;Norihiro Okinaka,&nbsp;Yoshihiro Nakatsuka","doi":"10.1021/acs.energyfuels.6c01098","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c01098","url":null,"abstract":"<p>The Collaborative Gas Hydrate R&amp;D Project in Alaska,a jointinitiative by the Japan Organization for Metals and Energy Security,the U.S. Department of Energy, and the U.S. Geological Survey, aimsto advance understanding of gas hydrate reservoir systems and theirproduction potential. As part of this effort, the HYDRATE 02 Geo DataWell (GDW) was drilled at the Kuparuk State 7-11-12 site to supporta long-duration production test and provide high-resolution petrophysicaldata for reservoir characterization. This study presents an integratedlog and core analysis of the B1 sand (unit B) hydrate-bearing reservoir,which was the focus of a 2023–2024 depressurization productiontest. Using a multicomponent inversion modeling program, we derivedcontinuous profiles of porosity, gas hydrate saturation, and intrinsicand effective permeabilities across the B1 sand and adjacent shaleintervals. The workflow uses well log and laboratory core data toinitialize the reservoir parameters and construct a multimineral reservoirmodel, then executes the multicomponent inversion solver to generatebest-estimated profiles for each key reservoir parameter. As a finalstep, data integration issues are investigated to assess the reliabilityof the inversion results. The modeling confirmed substantial heterogeneityin reservoir properties, with log- and core-derived porosities rangingfrom 10% to 40% and hydrate saturations increasing from near zeroto roughly 90% in localized zones within the B1 sand reservoir section.The core-based and nuclear magnetic resonance-derived estimates ofeffective permeability varied widely with depth across the B1 sandreservoir section, influenced by lithological variability and hydratedistribution. Comparisons between core measurements and log data confirmedthe reliability of the inversion results for porosity and intrinsicpermeability; however, inconsistencies remained in the analyses ofgas hydrate saturations and in the effective permeability estimateswithin the B1 sand reservoir section of the project-established GDW.Integrating petrophysical results from this study into future reservoirsimulations of the production test results, as completed within thecooperative gas hydrate research project in Alaska, may help resolvethese inconsistencies in the analysis of the B1 sand reservoir properties.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21269–21296"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depositional Environment and Diagenetic History of Gas Hydrate-Bearing Sediments of the Alaska North Slope (HYDRATE 02 Geo Data Well)","authors":"Stephen C. Phillips,&nbsp;Sarah J. Widlansky,&nbsp;Jun Yoneda,&nbsp;Akihiro Hiruta,&nbsp;Broden A. L. Grimm,&nbsp;Joel E. Johnson,&nbsp;Amy Geist,&nbsp;Melanie E. Holland,&nbsp;Peter J. Schultheiss,&nbsp;Timothy S. Collett","doi":"10.1021/acs.energyfuels.5c05174","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.5c05174","url":null,"abstract":"<p>We characterized the lithological, solid-phase geochemical,androck magnetic properties of sediment cores from subpermafrost strataon the Alaska North Slope collected as part of the U.S. Departmentof Energy (DOE), the Japan Organization for Metals and Energy Security(JOGMEC), and the U.S. Geological Survey (USGS) Collaborative GasHydrate Research and Development (R&amp;D) Project in Alaska. Pressurecores were recovered from the HYDRATE 02 Geo Data Well (GDW) at theKuparuk State 7-11-12 site through two hydrate-bearing sand reservoirs,the B1 and D1 sands, and their finer-grained bounding sediments. Boththe B1 and D1 sands are quartz-rich, chert-bearing, very fine litharenitesands. These submature to immature sands are poorly to moderatelysorted and angular with local fine-scale cross-stratification. TheB1 sand has larger grains and a lower clay content as compared tothe D1 sand. These sands are the upper portions of upward coarseningprogradational sequences. The clay- and silt-rich bounding muds exhibitfine-scale wavy and lenticular laminations, suggesting episodic highenergy deposition events. Overall, these sediments were depositedin a shoreface to nearshore marine environment during the Paleogene,modulated by changing depositional energy associated with sea levelvariation. Organic matter δ¹³C and C/N compositionof these sediments indicate a source mixture of land plants and freshwaterplankton, with possible minor presence of oil within the B1 sand.These sediments contain high and variable total sulfur (TS) content,suggesting porewater conditions influenced by variable salinity overtime. Rock magnetic analyses indicate precipitation of greigite inthe mud beneath the D1 sand, in the basal C shale overlying the B1sand, and the mud beneath the B1 sand, likely due to intervals ofsulfate limitation during periods of lower Arctic Ocean salinity.Based on pyrite abundance, TS, and δ³⁴S-TS composition,the D1 sand and bounding sediments experienced more substantial sulfideprecipitation. The unit E basal shale overlying the D1 sand containsa 0.25 m thick pyrite-dominant sand, indicating local bottom wateranoxic conditions. X-ray fluorescence scanning and discrete measurementsprovide additional supporting interpretation of the depositional anddiagenetic processes that have occurred at this site and track therelative amount of drilling fluid contamination with barium abundancein the core samples.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21241–21268"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the Interface of Plasma, Metal, and Catalyst Support in Plasma-Assisted Dry Methane Reforming on Pt-Based Catalysts","authors":"James L. Trettin,&nbsp;Janice M. Kankolongo,&nbsp;Cole W. Hullfish,&nbsp;Bruce E. Koel,&nbsp;Michele L. Sarazen","doi":"10.1021/acs.energyfuels.6c03688","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c03688","url":null,"abstract":"<p>Nonthermal plasma(NTP)-assisted dry methane reforming (DMR) onsupported metal catalysts has emerged as a promising method for sustainable,electrified conversion of methane (CH₄) and carbon dioxide(CO₂) into carbon monoxide (CO) and hydrogen (H₂), which are valuable chemical/fuel precursors and energy carriers.NTP-assisted DMR has been reported to enhance reaction rates and reducecatalyst deactivation relative to purely thermal operation. However,the complex interactions between the plasma, metal nanoparticles,and catalyst support under reaction conditions complicate mechanisticinterpretation and limit informed catalyst design. Here, plasma-assistedDMR on platinum (Pt) nanoparticles supported on alumina (Al₂O₃), silica (SiO₂), and zeolite 3A was investigatedin a coaxial packed-bed dielectric barrier discharge (DBD) reactorto increase understanding of how the plasma, metal, and support interactto govern activity, selectivity, and catalyst stability. The plasmaenhanced DMR turnover rates, altered selectivity among DMR, reversewater–gas shift (RWGS), and direct coupling of methane (DCM)pathways as indicated by CO, H₂, water (H₂O),and ethane (C₂H₆) formation rates, and reducedthe apparent activation barriers. The extents of all these plasma-inducedchanges were impacted by the catalyst identity. Properties of thesupport (e.g., basic site density and dielectric constant) affectedthe plasma power and catalytic performance, and the Pt nanoparticlesize impacted the plasma and product selectivity. Post-reaction characterizationand extracted deactivation rate constants revealed support-dependentcatalyst stability, including coke formation and Pt restructuring,with minimal sintering on Al₂O₃, significantagglomeration on 3A after plasma exposure, and reduced deactivationof Pt/SiO₂ under plasma-assisted conditions relative tothermal conditions. These results provide insight into the interplayof plasma, metal nanoparticles, and support in NTP-assisted DMR, withimplications for informed catalyst design and process optimizationin similar plasma-assisted catalytic C₁ upgrading systems.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21449–21463"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review and Outlook of CO2 Capture Using Alkali and Alkaline Earth Metal Oxide-Based Adsorbents: Powder Synthesis, Pelletization, and Reactor Design","authors":"Yifei Chang,&nbsp;Yaqi Li,&nbsp;Chenheng Zhangsun,&nbsp;Siyu Huang,&nbsp;Rui Luo,&nbsp;Cong Luo,&nbsp;Liqi Zhang,&nbsp;Xiaoshan Li,&nbsp;Fan Wu","doi":"10.1021/acs.energyfuels.6c03713","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c03713","url":null,"abstract":"<p>Alkali and alkaline earth metal oxide-based adsorbentshave attractedsignificant attention in the field of CO₂ capture due totheir good thermal stability, strong resistance to oxidative degradation,and low cost. This paper systematically reviews the research progressof the adsorbents from low-, medium-, to high-temperature regionsin three parts: material synthesis, particle forming, and reactorapplication. In the material part, modification strategies such asalkali metal doping and defect engineering have proven highly effectivein enhancing adsorption capacity. However, the sintering of activecomponents and pore collapse during cycling remain the key bottleneckslimiting the material’s lifespan. There is an urgent need toovercome these challenges through structural optimization and synergisticdesign of multiple components. At the particle-forming part, methodssuch as tableting, extruding-rounding, spray drying, gel-droplet,and 3D printing each have their own applicable systems and limitations.There is no universal solution for the trade-off between mechanicalstrength, porosity, and adsorption capacity of binders. In the reactorpart, fixed beds, fluidized beds, and moving beds respectively facedifferentiated deactivation mechanisms such as irreversible phasechange, wear, and thermal sintering, which put forward targeted requirementsfor the mechanical properties of adsorbent particles. At present,challenges such as the independent design of materials, molding, andreactors, and insufficient research on the competitive adsorptionof multiple components in real flue gas are prominent. In the future,it is necessary to strengthen multiscale collaborative optimizationto promote these alkali and alkaline earth metal oxide-based adsorbentsfrom the laboratory to industrial applications.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21034–21082"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permeability and Compressibility of “Seal” Sediment Overlying the B1 Sand Gas Hydrate Reservoir: Hydrate 02 Geo Data Well, Prudhoe Bay Unit, Alaska North Slope","authors":"Adrian V. Garcia,&nbsp;William F. Waite,&nbsp;Stephen C. Phillips,&nbsp;Jun Yoneda,&nbsp;Akihiro Hiruta,&nbsp;Timothy S. Collett","doi":"10.1021/acs.energyfuels.5c04831","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.5c04831","url":null,"abstract":"<p>Animportant element in evaluating the viability of extractingmethane from a gas hydrate-bearing reservoir is establishing the effectivenessof the overlying bounding sediment as a seal to prevent gas loss,to enable effective depressurization, and to prevent fluid from enteringthe reservoir during production. This laboratory study presents resultsfor index properties (e.g., grain density, grain size, and liquidlimit), compressibility and swelling indices, and permeability measurementson sediment overlying the gas hydrate-bearing reservoir that was thetarget of the recent JOGMEC-DOE-USGS collaborative gas hydrate productiontesting project on the Alaska North Slope (ANS). Sediment analyzedin this study was collected during pressure coring operations in theHYDRATE 02 Geo Data Well (GDW). The ∼6.1 m sediment intervalrecovered in Cores 13P and 14P (878.74–884.88 m measured depth,MD) exhibited heterogeneous sedimentologic characteristics at thecentimeter scale, with sediments ranging from clay to thin silty-sandlithologies. Permeability measurements and index-property correlationsindicate the interval’s overall in situ vertical permeabilityranges from 0.2 to 3.6 microdarcy (μD). Results for compressibility(<em>C</em>_C = 0.255 ± 0.02) and swellingindex (<em>C</em>_S = 0.04 ± 0.01) are consistentwith estimates based on mineralogy and liquid limit correlations.Based on the measured compressibility, the ∼3 MPa increasein effective stress during the stable phase of depressurization-inducedproduction is anticipated to have imposed 2.43 cm of compaction permeter in the reservoir overburden, reducing permeability by ∼36%.The overburden sediment’s low in situ permeability (3 to 4orders of magnitude below permeabilities measured in the gas hydrate-bearingpart of the B1 sand (unit B)) suggests the B1 sand′s overburdenprovides an effective seal. Such a seal promotes efficient productionby limiting fluid flow into the reservoir during depressurization-inducedgas hydrate dissociation.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"21213–21223"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149022660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen Stimulation Technology for Unconventional Oil and Gas Reservoirs: Current Application Status, Research Progress, and Future Outlook","authors":"Yuhan Zhou,&nbsp;Hu Jia,&nbsp;Yuanping Song,&nbsp;Hongyang Huang","doi":"10.1021/acs.energyfuels.6c02818","DOIUrl":"https://doi.org/10.1021/acs.energyfuels.6c02818","url":null,"abstract":"<p>Unconventional oil and gas resourcesare strategically importantand, owing to their vast scale, have become major alternatives toconventional hydrocarbons. Development remains difficult, however,because these reservoirs are generally heterogeneous, with low porosityand ultra-low permeability. Conventional stimulation may also pollutewater, damage formations, and entail high costs. Nitrogen, by contrast,is abundant, inexpensive and has low pollution potential. As a stimulationmedium, it can remove blockages, replenish reservoir energy, and improvedisplacement efficiency, making it well suited to unconventional reservoirdevelopment. This review follows the development of nitrogen energizationand divides the technologies into gaseous nitrogen, liquid nitrogen(LN₂), and composite systems. It describes how they work,their main features, and their application settings. Drawing on fieldresults from coalbed methane, shale, tight sandstone, and carbonatereservoirs, we summarize performance, explain the governing mechanisms,and compare their relative contributions under different reservoirconditions. We then examine the effects of reservoir properties, fluidcharacteristics, injection parameters, and freeze-thaw conditions.The discussion also covers the difficulties of transferring laboratoryfindings to field operations and the environmental footprint acrossthe technology lifecycle. Finally, we identify remaining technicalbarriers and propose directions for more efficient and environmentallyresponsible hydrocarbon development.</p>","PeriodicalId":35,"journal":{"name":"Energy & Fuels","volume":"40 38","pages":"20948–20978"},"PeriodicalIF":6.0,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}