Unconventional Resources最新文献

{"title":"Kaolinite origins and distinctive influences on deep-buried reservoir: A case study of Pinghu Formation in Xihu Depression, offshore China","authors":"Yanan Miao , Xin Li , Xiaofei Fu , Shu Jiang , Pengfei Wang , Xuejia Du , Xiaoxiao Leng , Wenjie Liu , Haoran Wang","doi":"10.1016/j.uncres.2025.100210","DOIUrl":"10.1016/j.uncres.2025.100210","url":null,"abstract":"<div><div>Substantial hydrocarbons in deep-buried reservoirs are challenged by diagenetically induced heterogeneity, hindering the identification of sweet-spot prospects. Despite being a common diagenetic mineral, genesis of kaolinite is rarely explored from a geochemical perspective, and much less is known about the effects of differential genetic kaolinite on reservoirs. In this paper, the distributary channel of Pinghu Formation in Xihu Sag was selected as a focused object. Petrological and geochemical analyses were conducted, including porosity/permeability test, light/electron microscope observation, electron probe test, and fluids inclusion measurement. In particular, hydrogen/oxygen (H/O) isotopes were applied to determine the genetic mechanisms of kaolinite. The results show that lithology types of distributary channel are mainly lithic arkose and feldspathic litharenite, with quartz comprising 65 %, feldspar sharing 16 %, and fragments sharing 19 % of the total sediments. Despite the uniformity of its detrital components, physical characteristics of the distributary channel exhibit significant variation. Porosity ranges from 3.3 % to 21.4 % (averaging 13.8 %), and permeability ranges from 0.02mD to 614.4mD (averaging 52.1mD). Furthermore, within individual channels, porosity/permeability values are high in the upper sections but fall in the lower. Kaolinite cementation can be observed in both the upper and lower channels, but exhibiting distinctive petrological and geochemical features. In the upper channels, kaolinite is characterized by an embedded-crystal form and low Mg/Ca/Fe content. Based on its high H/O isotopes (averaging −87.9 ‰ δD<sub>-SMOW</sub> and 12.3 ‰ δ<sup>18</sup>O<sub>-SMOW</sub>), the temperature of kaolinite cementation is estimated in the range of 90 °C–110 °C and the calculated δD<sub>water-SMOW</sub>/δ<sup>18</sup>O<sub>water-SMOW</sub> (averaging −90.7 ‰/-11.1 ‰) approached to the organic water region. These features suggest that kaolinite in the upper channels is the by-product of feldspar dissolution by organic acids. High kaolinite content indicates significant feldspar dissolution and extensive secondary dissolved pore space, which is a positive indicator of secondary pore development. In the lower channels, kaolinite is characterized by a sheet-crystal form and high Mg/Ca/Fe content. Based on its low H/O isotopes (averaging −103.8 ‰ δD<sub>-SMOW</sub> and 2.0 ‰ δ<sup>18</sup>O<sub>-SMOW</sub>), the temperature of kaolinite cementation is estimated in the range of 25 °C–50 °C, and the calculated δD<sub>water-SMOW</sub>/δ<sup>18</sup>O<sub>water-SMOW</sub> (averaging −60.5 ‰/-9.4 ‰) indicates a subsurface paleo-fluid environment. These features imply that kaolinite in the lower channels may derive from the recrystallization of muddy fragments. High kaolinite content indicates poor sorting, weak compaction resistance, and low dissolution extent, which negatively impacts both primary pore preservation and second","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"8 ","pages":"Article 100210"},"PeriodicalIF":0.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory evaluation of an innovative polyfraction nanoemulsion for enhanced oil recovery in carbonate reservoirs","authors":"Najeeb Anjum Soomro","doi":"10.1016/j.uncres.2025.100212","DOIUrl":"10.1016/j.uncres.2025.100212","url":null,"abstract":"<div><div>Polymers and nanoemulsions are frequently employed to boost enhanced oil recovery (EOR) systems' performance. Several physical phenomena that are essential to the process can be used in a synergistic way when both of these additives are used. Laboratory core flooding investigations utilizing natural cores are one way to evaluate these processes. Carbonate rocks are displaced by oil under extreme heat and pressure in a variety of studies. Tests are conducted on polymer solutions and a recently created polyfraction nanoemulsion. The test findings show that these compounds are stable at high temperatures, high pressures, and in the presence of H₂S, and they are useful for EOR operations. In the laboratory EOR simulation, the best results were obtained for polymer and nanoemulsion concentrations in diluted reservoir water of 0.05 % and 1 %, respectively. These concentrations were shown to be the most effective. The polymers continue to demonstrate a high level of effectiveness when it comes to the displacement of crude oil from carbonate rocks under these conditions. On the other hand, the nanoemulsion that was tested enhances the wettability of carbonate rocks and reduces interfacial tension, both of which are factors that promote the efficiency of oil displacement. When compared to the quantity that was accomplished with water that did not contain any additives, the oil recovery that was measured in this instance was 37.5 % higher.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"8 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced clustering techniques for lithofacies and electrofacies identification in post-salt carbonate and siliciclastic reservoirs: a case study from the campos basin, Brazil","authors":"Abel Carrasquilla ,&nbsp;Herson Rocha","doi":"10.1016/j.uncres.2025.100211","DOIUrl":"10.1016/j.uncres.2025.100211","url":null,"abstract":"<div><div>The effective characterization and management of hydrocarbon reservoirs require a thorough understanding of their petrophysical properties, from exploration to production. Modern borehole logging and interpretation techniques play a crucial role in reducing operational costs while enhancing reservoir evaluation. Petrophysical analysis is fundamental in this context, enabling the interpretation of subsurface lithology and the assessment of key rock-fluid interactions, including porosity, permeability, and fluid saturation. These parameters are essential for identifying source rocks, seals, reservoir zones, and aquifers. Geophysical well logs are among the most reliable tools for determining geological formations and their petrophysical attributes. This study investigates two post-salt reservoirs in the Campos Basin, southeastern Brazil, utilizing data from four boreholes - two as reference wells and two as blind tests. A conventional suite of well logs was employed to define electrofacies, supported by geological data. Initial cluster analysis was conducted using singular value decomposition, hierarchical clustering (dendrograms), neutron-density lithological cross-plots, and principal component analysis (PCA) to identify inherent groupings within the dataset. Subsequently, nine unsupervised classification techniques-including eight clustering algorithms (e.g., k-means, k-medoids, Gaussian mixture models, spectral clustering, k-nearest neighbors, subtractive fuzzy clustering, fuzzy c-means, and agglomerative hierarchical clustering) and one neural-based mapping method (competitive neural network) - were applied. The exploratory data analysis was essential to understand the statistical behavior and interrelationships among the petrophysical logs, serving as a foundational step for the effective application of the clustering algorithms. Despite the diverse mathematical foundations of the clustering algorithms, the three electrofacies were reliably correlated with lithofacies. In the siliciclastic reservoir, these corresponded to sandstone, shale, and limestone, while in the carbonate reservoir, they were classified as grainstones, wackestones, and cemented grainstones. This study highlights the efficacy of multi-algorithm clustering in petrophysical facies classification, providing a reliable framework for reservoir characterization in analogous geological settings.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"8 ","pages":"Article 100211"},"PeriodicalIF":0.0,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing photovoltaic panel efficiency through Water-Cooling: A parametric comparative evaluation of energetic, economic, and environmental benefits","authors":"Hassan Raad ,&nbsp;Samer Ali ,&nbsp;Jalal Faraj ,&nbsp;Cathy Castelain ,&nbsp;Khaled Chahine ,&nbsp;Mahmoud Khaled","doi":"10.1016/j.uncres.2025.100208","DOIUrl":"10.1016/j.uncres.2025.100208","url":null,"abstract":"<div><div>The pressing need for more effective solar technology is highlighted by the global transition away from fossil fuels and toward renewable energy sources. Despite the enormous potential of photovoltaic (PV) panels, efficiency losses in high-temperature conditions limit their performance. The purpose of this study is to theoretically evaluate the energy, financial, and environmental advantages of different water-cooling techniques intended to improve the sustainability and operating efficiency of PV panels. In contrast to traditional research, this work quantifies increases in energy output, cost savings, and CO₂ emission reductions across various cooling configurations by a thorough parametric analysis inside a single theoretical framework. To simulate how various water-cooling methods affect PV panel performance, a mathematical parametric model was created. Energy production, cost savings, and carbon footprint reduction were among the key performance metrics computed and compared for PV applications in relation to the consumption ratio R, which is defined as the ratio of the actual building load to the maximum PV power output, or the amount of energy consumed by the house from the PV panels.</div><div>With an annual energy gain of 1354.10R kWh per panel, cost savings of 582.26R USD, and CO₂ emission reductions of 785.37R kg, jet water impingement cooling (JWPV) outperformed the other technologies under evaluation. However, with energy gains of 1061.53R kWh, savings of 456.46R USD, and CO₂ reductions of 615.68R kg, evaporative cooling (EPV) produced the least amount of improvement. These results highlight how important efficient cooling is to improving PV panel performance and developing sustainable solar energy solutions.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100208"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifractal analyses on the retention mechanism of fracturing fluid in tight sandstone","authors":"Yan Zhang ,&nbsp;Zhiping Li ,&nbsp;Hao Wu","doi":"10.1016/j.uncres.2025.100209","DOIUrl":"10.1016/j.uncres.2025.100209","url":null,"abstract":"<div><div>Tight sandstone is defined by its low porosity, limited permeability, and considerable heterogeneity, necessitating hydraulic fracturing for hydrocarbon extraction. However, fracturing fluid often becomes retained within the reservoir, which can markedly reduce hydrocarbon extraction efficiency. The mechanisms behind this retention in tight sandstone remain unclear. In this study, we employed the centrifugation method to replicate the flowback and retention processes of fracturing fluid. We conducted low-pressure nitrogen gas adsorption (LP-N₂GA) experiments, nuclear magnetic resonance (NMR) analysis, and utilized combined multifractal methods to examine the alterations in pore structure and fluid distribution properties of sandstone samples. The LP-N₂GA experiments revealed that after fracturing fluid treatment, the surface area and pore volume of the samples diminished, whereas the average pore size expanded, and the pore size distribution range narrowed. Multifractal analysis indicated that post-treatment, the number of clustered pores decreased, pore connectivity improved, and distribution of pore sizes became more homogeneous. NMR experiments showed that during pressure-driven imbibition, fracturing fluid primarily occupied large pores, and at high imbibition pressures, the fluid within these large pores was more easily recovered. Conversely, in small pores, fracturing fluid was more likely to flowback under lower imbibition pressures. Further multifractal analysis demonstrated that with increasing flowback pressure, the connectivity of trapped fracturing fluid within the pores gradually deteriorates, while the clustering and distribution of the fluid initially decreased and then increased. These findings provide deeper insights into the mechanisms governing the fluid distribution changes during the fracturing fluid flowback process in tight sandstone.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100209"},"PeriodicalIF":0.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat production of sedimentary rocks in Chengdao-Kendong area, Bohai Bay basin","authors":"Xiaolin Liu ,&nbsp;Anyu Jing ,&nbsp;Yuanjin Sun ,&nbsp;Chao Sun ,&nbsp;Ruibo Jiang ,&nbsp;Xing Mu ,&nbsp;Xiaoxue Jiang ,&nbsp;Fang Xie ,&nbsp;Yaodong Xu ,&nbsp;Chuanqing Zhu","doi":"10.1016/j.uncres.2025.100207","DOIUrl":"10.1016/j.uncres.2025.100207","url":null,"abstract":"<div><div>Sedimentary heat flow, as part of terrestrial heat flow, plays a key role in hydrocarbon generation by affecting the temperature of source rocks, thus influencing the thermal evolution and maturity of organic matter. The radioactive heat production rate of rocks is essential for studying sedimentary heat flow. Based on empirical formulas proposed by previous researchers that relate natural gamma log to heat production rates, this study calculated 26,707 rock heat production rate data points from 60 wells in the Chengdao-Kendong area. Results show that the average heat production rate of the sedimentary layers is 1.06 ± 0.34 μW/m³,and the different lithologies are as follows: mudstone 1.28 μW/m³, sandstone 1.05 μW/m³, conglomerate 1.01 μW/m³, glutenite 0.93 μW/m³, limestone 0.44 μW/m³, dolomite 0.45 μW/m³.The radioactive heat production ranges from 3.0 to 6.8 mW/m². In the Changdi and Gudong areas, sedimentary layers contribute 6.3–10 % of the terrestrial heat flow, while the Kendong area's contribution is around 4.3 %. Moreover, the distribution of terrestrial heat flow is closely related to variations in basement depth, mainly influenced by mantle heat flow in the Chengdao-Kendong area.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100207"},"PeriodicalIF":0.0,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospect studies and geological CO2 storage potential in Nigeria","authors":"Victor Omefe ,&nbsp;Mahlon Kida Marvin ,&nbsp;Zakiyyu Muhammad Sarkinbaka ,&nbsp;Victor Inumidun Fagorite ,&nbsp;Aliyu Buba Ngulde","doi":"10.1016/j.uncres.2025.100206","DOIUrl":"10.1016/j.uncres.2025.100206","url":null,"abstract":"<div><div>Nigeria's dependence on fossil fuels has resulted in high CO₂ emissions. However, while the country's Nationally Determined Contribution (NDC) outlines a 20–47 % reduction in greenhouse gas emissions, the lack of enabling investment mechanisms and limited technological innovation continue to hinder the deployment of Carbon Capture, Utilization, and Storage (CCUS) technologies. Successful implementation of CCUS in Nigeria will depend on a combination of critical factors. These include the suitability and efficiency of the carbon capture technologies deployed, the level of technical readiness and local capacity, the economic feasibility in terms of operating and capital costs, and the integration of comprehensive life cycle assessments to ensure environmental and economic sustainability.</div><div>A recent study by the International Finance Corporation (IFC) estimated that Nigeria has a theoretical storage potential of about 10.7 gigatons. However, our review of basin-specific studies suggests that this estimate may be conservative while highlighting the Niger Delta as the most viable region for large-scale CO₂ sequestration. Despite these indicators, the absence of commercial-scale CCUS deployment, along with weak regulatory support and a lack of fiscal incentives, remain significant obstacles. The findings argue for a focused policy shift that leverages Nigeria's existing oil and gas infrastructure, enabling the clustering of CO₂ point sources to share transportation and injection facilities. Furthermore, expedited strategic partnerships with initiatives such as the Africa Carbon Markets Initiative (ACMI) could facilitate carbon credit development and improve economic viability. Pilot studies already demonstrate promising storage performance, supporting the argument for near-term demonstration projects. We highlight that with appropriate policy support, technology deployment, and international collaboration, geological CO₂ storage could play a critical role in Nigeria's trajectory toward climate and sustainable energy development. We offer practical recommendations for aligning CCUS deployment with national climate goals and enhancing investment readiness in the sector.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100206"},"PeriodicalIF":0.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive review on role of information technology in city gas distribution industry","authors":"Kriti Yadav ,&nbsp;Anirbid Sircar ,&nbsp;Namrata Bist","doi":"10.1016/j.uncres.2025.100202","DOIUrl":"10.1016/j.uncres.2025.100202","url":null,"abstract":"<div><div>India is quickly transitioning towards a gas-based society by expanding the proportion of natural gas in the nation's energy blend from 6 % to 15 % by 2030. India is investing around INR 1.2 trillion in the natural gas distribution of the city gas sector. The most recent developments in distribution include intelligent (acoustic and mechanical) methods for identification of leaks in pipelines, robotic examination, automated testing with ultrasound, thermal mass circulation detectors, geographical information systems, and intelligent carriers and cascade units. The role of the Internet of Things comes into the picture to bind all these digitalisation techniques into a smart technique. This infrastructure eliminates the need for human involvement by integrating different tools and technologies. It allows for the development of smarter cities across the world. This work reveals the possible uses of several internet techniques in the city gas distribution industry. The study introduces readers to the smart technologies used for Smart Gas Distribution, such as Geographical Information Systems, Supervisory Control and Data Acquisition Systems, Applications and Products in Data Processing, etc. The work also highlights the key challenges in the adaptation of these technologies in the gas distribution sector. The paper offers a thorough overview of the topic and motivates academicians and investors to employ a variety of internet solutions. The application of big data, artificial intelligence, and machine learning can contribute to several levels of city gas distribution. The potential risk factors and upkeep expenses might be eliminated with the presence of this intelligent network, with the help of artificial intelligence and machine learning. The distinctiveness that this study presents its ability to bring light on many technologies used in places such as North America, China, South Korea, and Europe, such as DecisionSpace365 and Birdz, and Silent Soft SA's for the gas industry.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100202"},"PeriodicalIF":0.0,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of CO2 and steam injection to optimise the recovery of gas from hydrate formation","authors":"Nneoma Juanita Okeke ,&nbsp;Solomon Asante-Okyere ,&nbsp;Alexander Ofori Mensah ,&nbsp;Zainab Ololade Iyiola ,&nbsp;Joseph Nii Boi Boye","doi":"10.1016/j.uncres.2025.100203","DOIUrl":"10.1016/j.uncres.2025.100203","url":null,"abstract":"<div><div>CO₂ and steam injection are currently recognised as two of the main methods for recovering gas from hydrates. Gas hydrates are vital components of the carbon cycle thought to hold more than fifty percent of all the hydrocarbon resources known world-wide. Such vast reserves are untapped because extraction is challenging. However, there is still a need to recover gas from hydrates to supplement the traditional sources with the increasing energy demand paired with depleting reserves. This research investigates methane recovery from a gas hydrate reservoir using CO₂ and steam injection while ensuring wellbore stability. Numerical simulation techniques were employed to evaluate extraction efficiency over injection periods of 1, 5, 15, 20, 30, and 365 days. The injection of both gases induced hydrate dissociation, leading to enhanced formation permeability, with steam injection leading to a more significant increase. Results showed 100 % hydrate dissociation and consequently a much higher gas production potential with steam, compared to 91 % dissociation and a lower gas production potential with CO₂ over one year. Based on these findings, this study recommends steam injection as the optimal method for methane recovery from hydrate formations due to its effectiveness in enhancing permeability while causing minimal formation perturbation.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100203"},"PeriodicalIF":0.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144279874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrocarbon forming condition and accumulation model of the buried-hill reservoir in the Beier sag, Hailar Basin","authors":"Yixuan Ran","doi":"10.1016/j.uncres.2025.100204","DOIUrl":"10.1016/j.uncres.2025.100204","url":null,"abstract":"<div><div>The Hailar basin is an important petroliferous basin in Northeast China, the buried-hill is not only the primary oil productive formation, but also an important unconventional resource and risk exploration target in Hailar Basin. However, relatively few studies have investigated the characteristic and forming condition of the buried-hill reservoir. This article describes the genesis and characteristic of different kinds of buried-hill, discusses the hydrocarbon forming condition, such as source rock, favorable reservoir, transport channel, hydrocarbon supply windows, cap rock, and their relationship with the buried-hill reservoir, and concludes by discussing the accumulation model. The result is that, the ranges of TOC and S₁+S₂ is 0.54–3.34 % and 4.34–18.13 mg/g, with an average value of 1.93 % and 6.84 mg/g, respectively. The Ro ranges from 1.02 % to 1.65 %, indicate the source rock in Nantun Formation is organic rich and thermally mature for hydrocarbon generation. The balanced profile recovery and seismic interpretation demonstrate that there are three kinds of buried-hill, named Pre-formed buried-hill, Syn-formed buried-hill and Post-formed buried-hill. The buried-hill can be divided into five layers, they are Fully weathered clay layer, Highly weathered fracture layer, Medium weathering pore layer, Weakly weathered compact layer and Inside fractured layer, from the top to bottom. The favorable reservoir are concentrate in the Medium weathering pore layer and Inside fractured layer.</div><div>The results indicate that the oil-bearing buried-hill is controlled by the union of different kinds of hydrocarbon forming condition. They are all nearby the oil-generating depressions in Beixi sub-sag and Beizhong sub-sag. The III-type faults are opened during the main accumulation period, which is the most important transport channel. The hydrocarbon supply windows determine the abundance of the oil reservoir. The Nantun Formation is the advantage steal rock and determine the distribution of oil reservoirs. We recognize two kinds of accumulation model, named “inside bedrock oil reservoir in the Post-formed buried-hill” and “weathering crust oil reservoir in the Syn-formed buried-hill”, and select the Huoermoduo buried-hill, Sudeerte buried-hill and Beizhong buried-hill as the favorable exploration target. The hydrocarbon in Huoermoduo buried-hill is concentrate in the inside bedrock reservoir, while the oil in Sudeerte buried-hill and Beizhong buried-hill are found in the weathering crust reservoir. The forming condition and pattern are different from each other, which is the main reason for the variation distribution of inside bedrock oil reservoir and weathering crust oil reservoir.</div></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"7 ","pages":"Article 100204"},"PeriodicalIF":0.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}