Marine and Petroleum Geology最新文献

{"title":"Why does widespread submarine creep occur on the low-gradient continental slope of the northern South China Sea?","authors":"Weijian Gao ,&nbsp;Wei Li ,&nbsp;Tiago M. Alves ,&nbsp;Song Jing ,&nbsp;Wenhuan Zhan","doi":"10.1016/j.marpetgeo.2025.107453","DOIUrl":"10.1016/j.marpetgeo.2025.107453","url":null,"abstract":"<div><div>Submarine creep concerns the slow, post- or syn-depositional gravity-driven motion of continental slope strata, and may evolve into submarine landslides that are large enough to cause catastrophic tsunamis. However, compared to other slope instability features, the factors controlling submarine creep are still poorly understood. By using bathymetric data, high-quality seismic profiles and attribute maps, this study investigates the factors contributing to submarine creep on the gentle (∼1°) continental slope of the northern South China Sea. Our results demonstrate that the presence of contourite drifts was a preconditioning factor for the development of creeping strata in the study area. Fluids accumulated at the base of a broad glide plane generated the overpressure required to initiate sediment creep. Remnant strata and slide blocks reduced the seal competence of a mass-transport deposit (MTD), forming high-permeability zones in which deep-seated faults propagated towards the surface. Faults within high-permeability zones provided long-term pathways for upward-migrating fluids, enabling it to weaken the stability of shallow strata. Subsequent long-term migration and accumulation of fluids within the moat adjacent to the MTD's high-permeability zone promoted the retrogressive propagation of the upslope glide plane. A combination of all these processes ultimately resulted in the development of a vast area of submarine creep during the Quaternary. Similar processes to these documented in South China Sea explain the onset of submarine creep phenomena on continental margins across the world.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"180 ","pages":"Article 107453"},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated analysis of the gas hydrate petroleum system in the western South Korea Plateau (WSKP), East Sea (Sea of Japan)","authors":"Kyoung-Jin Kim ,&nbsp;Bo-Yeon Yi ,&nbsp;Dong-Geun Yoo","doi":"10.1016/j.marpetgeo.2025.107459","DOIUrl":"10.1016/j.marpetgeo.2025.107459","url":null,"abstract":"<div><div>This study provides the first comprehensive definition of the late Neogene to Quaternary deepwater fan system and gas hydrate (GH) petroleum system in the western South Korea Plateau (WSKP). An integrated geological and geophysical approach was employed to evaluate reservoir, source, and preservation potentials, establishing the WSKP as a promising target for GH exploration. The late Neogene to Quaternary deepwater fan system comprises submarine canyons, slope channel systems, and lobe complexes, with Lobe 1 and Lobe 2 identified as high-potential reservoirs. These lobe deposits demonstrated favorable reservoir properties, including maximum thicknesses of 15–38 m and 11–28 m, respectively, high lateral continuity, and elevated net-to-gross ratios. Source potential was attributed to two tectonostratigraphic units (MS2 and MS3), which exhibited high total organic carbon (&gt;1.0 wt %) and hydrogen index values (&gt;200 mgHC/gTOC) for bioigenic gas generation. Organic-rich claystones deposited under hemipelagic conditions served as effective source rocks. The biogenic gas window (20–60 °C) was observed at depths of 250–750 ms below the seafloor, corresponding to MS2 and MS3 intervals. Fault systems facilitated efficient gas migration, enabling upward transport from source rocks in MS2 and MS3 to reservoirs in MS4. Preservation potential was corroborated by seismic indicators such as bottom simulating reflectors, seismic attribute anomalies, and amplitude versus offset responses. This study offers a framework for understanding the GH petroleum system in the WSKP, advancing knowledge on depositional systems and GH accumulation. The findings contribute to understanding GH systems in back-arc basins and provide a foundation for future exploration.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"180 ","pages":"Article 107459"},"PeriodicalIF":3.7,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methane clumped isotopes of shallow gas hydrates in the Haima cold seeps, South China Sea: Implications for marine carbon cycling and sequestration","authors":"Haodong Chen ,&nbsp;Jing Zhao ,&nbsp;Qianyong Liang ,&nbsp;Jiacheng Li ,&nbsp;Junxi Feng ,&nbsp;Xi Xiao ,&nbsp;Zongheng Chen ,&nbsp;Yun Li ,&nbsp;Yongqiang Xiong","doi":"10.1016/j.marpetgeo.2025.107449","DOIUrl":"10.1016/j.marpetgeo.2025.107449","url":null,"abstract":"<div><div>Determining the methane sources and sinks of natural gas hydrates is pivotal to understanding carbon cycling over geological history. However, methane sources in natural gas hydrates remains poorly understood. In this study, we collected samples of hydrate-bound gas and pore fluid from shallow sediments in the Haima cold seeps of the Qiongdongnan Basin, South China Sea, and conducted various geochemical analyses to identify the sources and sinks of methane in this area. Particularly, methane clumped isotopes, an emerging method for tracing methane sources and sinks, were applied. Our results indicate that thermogenic methane accounts for 47.3 % of the shallow gas hydrates in the seeps, microbial methane being the rest. Furthermore, the data of headspace gas and pore water indicate the trace of anaerobic oxidation of methane (AOM) in the methane captured in shallow gas hydrates. By comparing our results with published datasets for deep gas hydrates, we refined the generation and accumulation span of biogenic methane as the Pliocene to Quaternary. Findings from this study highlight the contributions from different sources to hydrate-bound gas in the Qiongdongnan Basin and the coupled relationship between shallow gas hydrate formation, and deep oil and gas reservoirs. Our work advances the understanding of methane gas depletion and carbon sequestration in shallow sediments associated with cold seeps, and enhances the knowledge basis for the future exploitation of natural gas hydrates.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"180 ","pages":"Article 107449"},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating gas hydrate saturation in sediments using geophysical methods","authors":"Linsen Zhan,&nbsp;Wenjiu Cai,&nbsp;Haotian Liu,&nbsp;Ran Yang,&nbsp;Shiyuan Shi,&nbsp;Hailong Lu","doi":"10.1016/j.marpetgeo.2025.107458","DOIUrl":"10.1016/j.marpetgeo.2025.107458","url":null,"abstract":"<div><div>Quantifying the presence of gas hydrates within sediments is essential for accurately assessing their resource potential and effectively exploiting gas hydrate-bearing sediments (GHBS). Common geophysical methods for determining gas hydrate saturation include well-logging, seismic reflection, and controlled-source electromagnetic (CSEM) surveys, which detect changes in the electrical and acoustic properties of sediments. However, different methods can yield varying saturation estimates even within the same area, and the applicability of these techniques has not been fully explored. This review examines the typical anomalies associated with gas hydrate presence in seismic, well-logging, and CSEM surveys, assessing the underlying principles, strengths, and limitations of each of these geophysical methods. Case studies and method comparisons illustrate the application of these techniques across various geological settings, emphasizing the complex interplay between hydrate saturation, sediment properties, and measurement frequencies. Characterizing GHBS using geophysical methods remains challenging due to the oversimplification of rock physical models for natural gas hydrate systems, as well as the discrepancies between pore-scale distribution and larger scales of geophysical measurement tools. To address these issues, advanced rock physics models that integrate resistivity and elastic properties – while accounting for the coexistence of gas hydrates and free gas, as well as anisotropic sediment behavior – are essential for improving the accuracy of saturation estimates. Additionally, resolving scale-related discrepancies through advanced upscaling techniques and integrated multi-disciplinary datasets is critical for reliably extrapolating localized hydrate saturations to reservoir-scale resource evaluations.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107458"},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated 3D forward stratigraphic and basin modeling of the Santos Basin, offshore Brazil: Implications of sedimentary depositional facies and CO2 migration for silicification of continental carbonate reservoirs","authors":"Alina-Berenice Christ ,&nbsp;Marie-Christine Cacas-Stentz ,&nbsp;Nathalie Collard ,&nbsp;Fadi Henri Nader ,&nbsp;Elisabeth Bemer ,&nbsp;Rodrigo Brandão Bunevich ,&nbsp;João Paulo Borges Gomes ,&nbsp;Olinto Gomes de Souza Jr. ,&nbsp;Maria Anna Abreu de Almeida dos Reis","doi":"10.1016/j.marpetgeo.2025.107455","DOIUrl":"10.1016/j.marpetgeo.2025.107455","url":null,"abstract":"<div><div>Silicification plays an important role in the quality of pre-salt reservoirs, resulting in significant heterogeneities that are difficult to predict. A better understanding of the distribution of silicified pre-salt reservoirs at the basin scale helps in mapping such heterogeneities and further optimizing responsible hydrocarbon exploration and production. Here we investigate a scenario involving the interaction of an internal silica source from Mg-rich clay (sedimentary depositional facies) and CO₂-rich fluid upwelling along deep-rooted faults. These are some of the main controlling factors of silicification, as confirmed with conceptual and numerical geochemical modeling. We present a new modeling workflow integrating forward stratigraphic modeling (FSM), basin/thermal modeling, quantitative chemical modeling, and map-based analysis to derive silicification probability maps of the Barra Velha Formation in the Santos Basin (Brazil). FSM simulates, with a process-based approach, the sediment distribution in the Barra Velha Formation including Mg-rich clay. Basin/thermal modeling simulates the rock-fluid systems evolution, CO₂ migration, accumulation, and concentration in the formation. Geochemical modeling provides Mg-clay transformation ratios depending on Mg-clay content of rock matrix and CO₂ concentration. Combining all elements together enables calculation of basin scale silicification probability maps across the study area. Highest probability of silicification is found above uplifted areas known to include Mg-rich clay, intense faulting, and trapping structures.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"180 ","pages":"Article 107455"},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widespread shallow-marine anoxia in Late Ordovician epicratonic seas of eastern Laurentia: Evidence from lithological and geochemical proxies","authors":"Dan Atasiei ,&nbsp;Jisuo Jin ,&nbsp;Karem Azmy ,&nbsp;Cameron J. Tsujita ,&nbsp;Frank Brunton","doi":"10.1016/j.marpetgeo.2025.107454","DOIUrl":"10.1016/j.marpetgeo.2025.107454","url":null,"abstract":"<div><div>The Late Ordovician experienced dramatic episodes of globally widespread accumulation of organic-rich marine sediments as represented by black shales and their carbonate equivalents, often associated with ocean anoxia. During the mid-Katian, a widespread lithofacies of black, laminated, organic-rich marlstones, referred to as BLORMs (new term) in eastern Laurentia, contain abundant benthic shelly fossils, such as brachiopods and large trilobites that are incompatible with anoxic water conditions previously suggested for the facies. Here, we present lithological, paleontological, and geochemical data to demonstrate that the BLORM facies accumulated in shallow epicratonic seas under predominantly suboxic conditions punctuated by frequent intervals of anoxia. Organic-rich laminae were the result of frequent eutrophication events associated with nutrient enrichment from weathering inputs enhanced by Taconic orogenic phases, and cool-water upwelling from the Appalachian Foreland Basin. The transitions from the normal-marine limestone of the Cobourg Formation to the Collingwood BLORM facies, and then to clay shale of the Blue Mountain Formation in southern Ontario represented oceanographic signals or changes resulting in widespread shallow-marine anoxia and a regional collapse of the carbonate factory in eastern Laurentia. The drastic increase in clay influx and decrease in TOC contents in the clay shale of the middle-upper Blue Mountain Formation mark the end of BLORM depositional conditions. The variations in the weathering (Rb/Sr, Al/Ti, ∑REE), redox (Cr, V, Mo, U, Th/U) and primary productivity (TOC, δ¹⁵N, Zn, P) proxies reflect the fluctuations of sea level and the influence of the Taconic orogenic pulses on siliciclastic inputs into the marine environment. The TOC, δ¹⁵N and P_org profiles show distinct shifts that peak at a stratigraphic level correlated with the base of the Blue Mountain Formation and a significant increase in siliciclastic inputs as reflected by the climbing Rb/Sr, Al/Ti and ∑REE profiles, which is consistent with sedimentological evidence.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107454"},"PeriodicalIF":3.7,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oceanic redox variations during the Cambrian Age 2–3 in the Yangtze Block of South China: Evidence from pyrite-based proxies","authors":"Fangliang Fu ,&nbsp;Caineng Zou ,&nbsp;Zhengfu Zhao ,&nbsp;Songqi Pan ,&nbsp;Wei Wang ,&nbsp;Cui Luo ,&nbsp;Ganlin Hua ,&nbsp;Guanwen Lu ,&nbsp;Ming Yuan ,&nbsp;Jia Yin ,&nbsp;Zhenhua Jing","doi":"10.1016/j.marpetgeo.2025.107438","DOIUrl":"10.1016/j.marpetgeo.2025.107438","url":null,"abstract":"<div><div>The early Cambrian marks a pivotal period in metazoan evolution and ocean oxygenation through Earth's history, with sedimentary sequences in the Yangtze Block of South China preserving key records about biological and environmental evolution. Although previous studies have focused on redox conditions in shelf, slope, and basin environments, their controls on pyrite sulfur isotope (δ³⁴S_py) variations, and the influence of redox dynamics on biological activity within intraplatform basin remain unclear. This study presents results including diagnostic fossils, pyrite morphology, iron speciations, and δ³⁴S_py from the shales of the early Cambrian Qiongzhusi Formation in well W207, which is located in an intraplatform basin of the Yantze Block. These data are integrated with previous datasets from eight sections spanning shelf, slope, and basin environments. Our results indicate that during the transgression at the Cambrian Age 2–3 boundary (∼524–520 Ma), mid-depth euxinic waters on the slope expanded into the intraplatform basin, as supported by most samples with Fe_HR/Fe_T &gt; 0.38, Fe_py/Fe_HR &gt; 0.7, high Mo_EF/U_EF ratio (mean 5.2) and small sizes of framboidal pyrite (6.41 ± 0.70 μm). In contrast, in the early Cambrian Age 3 (∼520–517 Ma), these geochemical proxies collectively suggest widespread shelf oxygenation, coinciding with occurrence of abundant animal fossils in the strata. The seawater oxygenation probably facilitated metazoan diversification during the Cambrian explosion within the intraplatform basin. Deep-water oxygenation together with emerging bioturbations on the shelf shifted the oxic-anoxic redox interface from bottom water into sediments, promoting the formation of pyrite with heavy δ³⁴S_py values within seidments. Therefore, a spatial δ³⁴S_py gradient is observed during early Cambrian Age 3, with higher δ³⁴S_py values from the shallow shelf (more oxygen-rich) and deep basin (isotopically heavier sulfate in seawater) than those from middle-depth slope. The findings provide new insights into the redox landscape and its impact on biogeochemical cycling and metazoan evolution in the Yangtze Block during the early Cambrian.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107438"},"PeriodicalIF":3.7,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to ‘Quantification of free and adsorbed fluid content in shale oil reservoirs: Insights from preserved cores and different methods’ [Mar. Petrol. Geol. 177 (2025) 107400]","authors":"Hongrui Zhang ,&nbsp;Jinbu Li ,&nbsp;Wanglu Jia ,&nbsp;Min Wang ,&nbsp;Ping'an Peng","doi":"10.1016/j.marpetgeo.2025.107451","DOIUrl":"10.1016/j.marpetgeo.2025.107451","url":null,"abstract":"","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107451"},"PeriodicalIF":3.7,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144090678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic organic matter accumulation in a plateau salinized lacustrine basin: Major controls and hydrocarbon significance","authors":"Peng Pang ,&nbsp;Di Xiao ,&nbsp;Kunyu Wu ,&nbsp;Songtao Wu ,&nbsp;Haoting Xing ,&nbsp;Ying Xiong ,&nbsp;Rui Liu ,&nbsp;Xiucheng Tan","doi":"10.1016/j.marpetgeo.2025.107435","DOIUrl":"10.1016/j.marpetgeo.2025.107435","url":null,"abstract":"<div><div>Exploring the sedimentary process and organic matter enrichment mechanism of plateau saline lake basin holds unique theoretical research and practical production significance for the paleoenvironment restoration and hydrocarbon exploration in the plateau. This study aims to analyze the high-frequency sedimentary evolution and organic matter enrichment mechanism of the mixed deposits from the Eocene Lower Ganchaigou Formation (LGCG) in the Qaidam Basin on the Tibet Plateau, by means of petrology, mineralogy, and organic-inorganic geochemistry. Lithological characteristics indicated the high-frequency sedimentary sequences (&lt;10m) of the LGCG which are identified by a single cycle with four lithofacies from bottom to top: massive sandstones, laminated silty shales, laminated limestones, and bedded dolomites. Bulk organic geochemistry data showed the periodic variations of organic matter contents in the high-frequency sedimentary cycles. Organic matter predominantly occurs in dark gray laminated limestones, followed by the laminated silty shales, with the lowest contents in the bedded dolomites and massive sandstones. Inorganic geochemical proxies implied the cyclical changes of paleowater properties, paleoproductivity and sedimentation rate in the vertical profile that conformed to the high-frequency sedimentary sequences. Correlation analysis revealed that the enrichment of organic matter in the plateau saline lake is mainly related to high paleoproductivity and low sedimentation rate (&gt;5 cm/ka), and anoxic and low-salinity water conditions also promote the preservation of organic matter. Distinct from typical saline lake basins, the LGCG in the Qaidam Basin, a plateau saline lake, is characterized by lower organic matter abundance and higher hydrocarbon generation efficiency, due to reduced biological productivity and terrigenous input.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107435"},"PeriodicalIF":3.7,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing CO2 hydrate storage and avoiding leakage: Numerical analysis of the self-restoring formation process of hydrate caps in submarine sandy silts","authors":"Mengyang Li ,&nbsp;Shuanshi Fan ,&nbsp;Yanhong Wang ,&nbsp;Xuemei Lang ,&nbsp;Gang Li","doi":"10.1016/j.marpetgeo.2025.107450","DOIUrl":"10.1016/j.marpetgeo.2025.107450","url":null,"abstract":"<div><div>The sequestration of CO₂ in the form of hydrate within submarine sediments represents a promising strategy in Carbon Capture and Storage (CCS). However, the internal mechanisms governing CO₂ hydrate formation in sandy silty strata remain unclear. This paper established a multi-field coupled numerical model to simulate the formation process of CO₂ hydrate cap in a sandy silty layer in medium-depth seawater depth in the South China Sea for the first time and to evaluate the effects of different formation and injection parameters on the sealing capacity and leakage capacity. The results show that the optimum formation parameters are an initial permeability of 100mD and water saturation of 0.3. The porosity has the least effect on the sealed storage in the range of 0.2–0.4. The pressure of the injection well is slightly higher than the formation pressure and the temperature is close to the phase equilibrium temperature to achieve the ideal sealing effect. The region with high liquid CO₂ saturation shows horizontal diffusion between 200 and 400m. In addition, the high-pressure zone extended approximately 150m from the wellhead, with the final temperature diffusion matching the injection well up to about 20m from the wellhead. In the range of 150-400mbsf, a higher injection well location forms a broader lateral hydrate cap and a wider liquid CO₂ seepage range. This study provides theoretical guidance for selecting suitable formations and ensuring effective leakage control of specific sandy silty strata in the South China Sea at medium depth.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"179 ","pages":"Article 107450"},"PeriodicalIF":3.7,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}