Gas Science and Engineering最新文献

{"title":"Hydrogen purification via hydrate-based methods: Insights into H2-CO2-CO hydrate structures, thermodynamics, and kinetics","authors":"Ying Teng ,&nbsp;Yinlong Li ,&nbsp;Ting Huang ,&nbsp;Yiqi Chen ,&nbsp;Pengfei Wang ,&nbsp;Bin Wang ,&nbsp;Senyou An ,&nbsp;Yun Li ,&nbsp;Songbai Han ,&nbsp;Jinlong Zhu ,&nbsp;Yuze Wang ,&nbsp;Bin Chen ,&nbsp;Jianbo Zhu ,&nbsp;Heping Xie","doi":"10.1016/j.jgsce.2024.205484","DOIUrl":"10.1016/j.jgsce.2024.205484","url":null,"abstract":"<div><div>Hydrate-based H₂ purification is promising for removing impurities owing to the cage-like structures formed by water molecules. Understanding the competition mechanism of multicomponent gas molecule in hydrate is critical for improving gas purification efficiency. This study investigated the hydrate structure, thermodynamics, and kinetics of ternary gas mixture (H₂–CO₂–CO) from natural gas reforming products. The results identified H₂–CO₂–CO hydrate as type sI and determined the lattice parameters using X-ray diffraction. Raman spectroscopy results confirmed the presence of H₂, CO₂, and CO gas molecules in the hydrate phase. Increasing pressure, compared to cooling, enhanced CO₂ content in hydrate phase. The phase equilibrium conditions and average hydrate dissociation enthalpy (53.47 J/g) were determined using a high-pressure microcalorimeter. Gas chromatography identified that the content of CO₂ in the hydrate was the highest, followed by H₂, and CO was the least abundant. The molecule dynamics simulation results show CO₂ molecule numbers reflected trends in 5¹²6² cages, H₂ numbers correlated with changes in 5¹² cages, while CO numbers showed insignificant variation. Under the gas composition studied, the ability of gas molecules to be incorporated within hydrates decreases in the following order: CO₂, H₂, and CO.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205484"},"PeriodicalIF":0.0,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539555","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":"The displacement behaviors of CH4-containing anthracite under various injection pressures: The critical role of mineral dissolution and precipitation","authors":"Wenyu Fu ,&nbsp;Yunzhong Jia ,&nbsp;Zhaolong Ge ,&nbsp;Chenqing Shang ,&nbsp;Xinge Zhao","doi":"10.1016/j.jgsce.2024.205480","DOIUrl":"10.1016/j.jgsce.2024.205480","url":null,"abstract":"<div><div>Accurate prediction of CH₄-containing anthracite replacement and storage efficiency under supercritical CO₂ (Sc-CO₂) injection is crucial for enhancing both coalbed methane production and CO₂ geological storage. This study investigates pore structure evolution, mineral dissolution/precipitation characteristics, and their effects on adsorption behavior and storage efficiency at various injection pressures using GC, LT-N₂, SEM-EDS, and XRD analyses. Results show increased CH₄ adsorption in CH₄-containing anthracite due to CO₂ injection, influenced by injection pressure. The highest storage efficiencies of 24.95% and 24.36% were observed at 7.59 MPa and 10.81 MPa, respectively. Adsorption selectivity shifts from CH₄ to CO₂ with increasing pressure (&gt;10.81 MPa). Injection pressure affects specific surface area (SSA) and pore volume (PV), reducing them by 7.16% and 25.68%, respectively. Fractal dimension <em>D</em>_<em>L2</em> exceeds <em>D</em>_<em>L1</em> and decreases gradually. Silicate mineral surfaces become rough, which causes irregular cracks. Meanwhile, secondary precipitation consists mainly of carbonate minerals. Micropores exhibit lower non-homogeneity than mesopores, and overall pore structure complexity diminishes. Mineral dissolution/precipitation mechanisms expand storage space and enhance Sc-CO₂ interaction with CH₄-containing anthracite. These findings provide new insights into displacement behaviors of CH₄-containing anthracite seams after CO₂ injection, which can be valuable for guiding efficient injection of CO₂-ECBM.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205480"},"PeriodicalIF":0.0,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534533","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":"Agglomeration-dispersion effects of coal fines to control the permeability of propping fractures: A visual experimental study","authors":"Zixiang Han ,&nbsp;Shuaifeng Lyu ,&nbsp;Ao Lu ,&nbsp;Lichao Chen ,&nbsp;Quanming Chen ,&nbsp;Haichao Xing","doi":"10.1016/j.jgsce.2024.205474","DOIUrl":"10.1016/j.jgsce.2024.205474","url":null,"abstract":"<div><div>Coal fines are carried from coal seams during hydraulic fluid return, which affect the permeability of its propping fracture and efficiency of coalbed methane (CBM) extraction. Aggregates are the presentation form of coal fines typically. However, the impact of the two opposing coal fine states, agglomeration and dispersion, on the permeability of propping fractures is not clear. This work employed sodium dodecyl benzene sulfonate (SDBS) which is an anionic surfactant to regulate the condition of coal fines. Sand-packed tube tests with visual feedback were used to analyze the impacts of coal fines' agglomeration-dispersion effects under varying pressures. The findings showed that SDBS efficiently disperses coal fines in hydraulic fluid, increasing the amount of coal fines with tiny particle sizes in the range of 0–20 μm. The zeta potential test revealed that adding SDBS to coal fines enhances their surface's negative charge, strengthening the repulsive force between particles. Moreover, SDBS solution has better wetting properties on coal fines, which aids in the coal fines' dispersion. Consequently, the dispersion impact of SDBS on coal fines causes an increase in filtering loss and a delay in the filling of coal fines in propping fractures. Initially, SDBS improves the dispersion of coal fines that are more likely to pass through proppants, which lessens the damage to the propping fractures' permeability coefficient. In the end, coal fines in the fracture's front end form a denser filter cake, which significantly reduces the permeability coefficient of propping fractures. It was observed that the higher the pressure differentials, the greater damage to the permeability. Finally, field cases from two CBM wells validated that with increasing of hole bottom pressure, coal fines raised in the discharged water. Moreover, fracturing fluids with SDBS could promote the discharge of coal fines. The work can offer insightful information about coal fines control.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205474"},"PeriodicalIF":0.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534531","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":"Evaluation of the synergic effect of amino acids for CO2 hydrate formation and dissociation","authors":"Abdulrab Abdulwahab Almashwali ,&nbsp;Samson Foo Kong Jee ,&nbsp;Bhajan Lal","doi":"10.1016/j.jgsce.2024.205473","DOIUrl":"10.1016/j.jgsce.2024.205473","url":null,"abstract":"<div><div>Gas hydrate formation is a very challenging problem in the oil and gas industry. The chemical inhibition method is the best practicable hydrate mitigation method by injecting hydrate inhibitors such as Thermodynamic Hydrate Inhibitors (THIs) and Kinetic Hydrate Inhibitors (KHIs) into the pipeline. However, the hydrate inhibitors' biodegradability and limited data on dual functional inhibitor mixtures raise concerns in this study. This study aims to investigate and compare thermodynamic and kinetic inhibition on CO₂ hydrate by using biodegradable amino acid inhibitor mixtures of Glycine and Alanine. In this study, the inhibitor mixtures were prepared by mixing Glycine and Alanine in 3 different mixture ratios, followed by the Thermodynamic and Kinetic inhibition tests. Thermodynamic Inhibition Test was conducted by using 10 wt% of inhibitor mixtures in a CO₂-water system under pressure of 4.0, 3.5, 3.0 and 2.5 MPa, while Kinetic Inhibition Test was carried out by using 1 wt% of the sample in the CO₂-water system at a constant pressure of 4.0 MPa and temperatures at 274.15K. The analysis methods for the Thermodynamic Inhibition Test were Hydrate Liquid-Vapor Equilibrium (HLVE) Curve, Average Depression Temperature and Molar Dissociation Enthalpy, while the Induction Time method, the number of CO₂ moles consumed, the formation rate of CO₂ gas hydrate and RIP were used in the Kinetic Inhibition Test. In this study, all inhibitor mixtures exhibit dual functional inhibition on the CO₂ hydrate. For THI, 50% Gly: 50% Ala shows the best thermodynamic inhibition strength with an average depression temperature of 2.42 K. All the inhibitor mixtures for THI have the dissociation enthalpies within the CO₂ hydrate enthalpy range, which show that the inhibition is due to the influence on the water molecules’ interaction only. For KHI, 75% Gly: 25% Ala shows the highest kinetic inhibition strength on CO₂ formation with the longest induction time of 115.2 min and the highest RIP of 0.40. In the KHI experiment, there is a drop in the CO₂ uptake capacity with the presence of inhibitors used, where the highest difference of CO₂ moles consumed is 0.0057 mol. A synergistic effect of inhibitor mixtures was observed in this study on 50% Gly: 50% Ala for THI and 75% Gly: 25% Ala for KHI. However, the “degradation” effect was also exhibited on 75% Gly: 25% Ala and 25% Gly: 75% Ala for THI and 50% Gly: 50% Ala and 25% Gly: 75% Ala for KHI, where the performance of the inhibitor mixtures is poorer than the concentrated amino acids. The “degradation” effect of the inhibitor mixtures at certain ratios was not covered in this study and it requires a further understanding of the chemistry behind the inhibition mechanism.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205473"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534680","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":"Microstructural response of coal fracture surface induced by ScCO2 injection measured with AFM","authors":"Yidong Li ,&nbsp;Jienan Pan ,&nbsp;Haichao Wang ,&nbsp;Zhenzhi Wang ,&nbsp;Xianglong Wang ,&nbsp;Meng Li ,&nbsp;Yunbo Li","doi":"10.1016/j.jgsce.2024.205471","DOIUrl":"10.1016/j.jgsce.2024.205471","url":null,"abstract":"<div><div>Fractures in coal serve as the principal channels for the migration of coalbed methane (CBM). The microscopic traits of coal fracture surface are of significance for evaluating reservoir permeability and directly influence the outcome of CO₂ storage and displacement. To comprehend the impact of CO₂ on the coal fracture surface, the alterations in the coal fracture surface before and after CO₂ injection are investigated vis atomic force microscopy. As CO₂ gradually transforms into a supercritical state, the fracture density and aperture on the coal fracture surface gradually escalate. The mean pore size and porosity of the coal fracture surfaces rose from 5.45 nm to 6.55 nm and from 4.66% to 6.85%, respectively. The proportion of micropores (&lt;2 nm) gradually diminished. The proportions of mesopores (2–50 nm) and macropores (&gt;50 nm) proportions gradually. Swelling, extraction and mineral dissolution are the predominant reasons for the alteration in the pore structure of the coal fracture surface. CO₂ injection modifies the roughness and fractal characteristics of the coal fracture surface. The mean roughness <em>R</em>_<em>a</em> dropped from 6.54 nm to 4.03 nm, and the fractal dimension <em>D</em>_<em>s</em> declined from 2.45 to 2.28. With the fixed scanning range, the injection of CO₂ has been shown to reduce the roughness of coal fracture surface and lower their fractal dimension, thereby has a positive influencing permeability enhancement. Therefore, in CO₂-ECBM engineering, it is essential not only to analyze the physical properties of the target reservoir, but also to conduct a comprehensive evaluation of permeability with a suitably defined area of the reservoir.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205471"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534532","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":"Insights into the development of carbon molecular sieve membranes from polymer blends for gas separation: A review","authors":"Thaís Martins Neves,&nbsp;Liliane Damaris Pollo,&nbsp;Nilson Romeu Marcilio,&nbsp;Isabel Cristina Tessaro","doi":"10.1016/j.jgsce.2024.205472","DOIUrl":"10.1016/j.jgsce.2024.205472","url":null,"abstract":"<div><div>This study analyzes carbon molecular sieve membranes (CMSM) derived from the pyrolysis of polymer blends. While many studies have focused on modifying polymeric precursors to enhance CMSM performance, blending polymers provides a cost-effective method for creating materials with unique characteristics. However, the literature on CMSM derived from polymer blends is limited. This paper offers background information on CMSM structure and examines parameters affecting their gas separation performance, including the properties of polymeric precursors, blend composition, and pyrolysis conditions. Additionally, it provides valuable insights into unexplored blends for CMSM development, as well as methods to improve the miscibility of polymer blends.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205472"},"PeriodicalIF":0.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534537","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":"Perforation design coupled with heterogeneity during underground hydrogen storage in steeply dipping anticline aquifers","authors":"Mohammad Zamehrian,&nbsp;Ipsita Gupta,&nbsp;Mehdi Zeidouni","doi":"10.1016/j.jgsce.2024.205470","DOIUrl":"10.1016/j.jgsce.2024.205470","url":null,"abstract":"<div><div>Hydrogen has been recognized as a crucial energy carrier to reduce greenhouse gas emissions. However, as it is not always possible to meet current energy demands, underground hydrogen storage (UHS) is required for energy supply and consumption. UHS is an emerging field of study with limited investigations regarding structural conditions and wellbore perforation design in steeply dipping anticline aquifers. This study investigates different perforation schemes with respect to UHS within steeply dipping anticline aquifers to find the most suitable injection/production design while examining small-scale reservoir heterogeneities. Several UHS improvement techniques are evaluated, including water and CO₂ injection through flank wells during hydrogen production. The results indicate that the highest hydrogen production is achieved with a fully perforated H₂ well located at the crest as it provides the maximum contact between the hydrogen and aquifer layers during H₂ injection/production. In contrast, hydrogen production is diminished with increased heterogeneity, as higher heterogeneities raise the chance of H₂ being trapped. To enhance UHS performance, first H₂ initialization before UHS beginning was evaluated but the results showed that it does not enhance UHS performance in a steeply dipped anticline aquifers, as effectively as it does in gas reservoirs. Water injection from flank wells during H₂ production cycles showed improvement in hydrogen withdrawal, while water production experienced a slight increase. CO₂ injection from flank wells was evaluated to effectively increase H₂ recovery as a cushion gas and to maintain hydrogen purity during production. According to results, hydrogen purity was not affected only in high heterogeneity, since more hydrogen gets trapped in the small-scale high heterogeneity level, which prevents the mixing zone from reaching the H₂ well during production. While the method prevents hydrogen contamination in anticline aquifers due to the high dip angle coupled with high heterogeneity levels, it leads to a lower hydrogen recovery.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205470"},"PeriodicalIF":0.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534534","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":"Kinetic study on the effect of ice nucleation and generation on methane hydrate dissociation below the quadruple point","authors":"Ting-Ting Zhang ,&nbsp;Bo Li ,&nbsp;Wen-Na Wei ,&nbsp;Jing-Chun Feng ,&nbsp;Qing-Cui Wan","doi":"10.1016/j.jgsce.2024.205468","DOIUrl":"10.1016/j.jgsce.2024.205468","url":null,"abstract":"<div><div>Natural gas hydrates (NGHs) have captured worldwide attention because of its huge resources and high energy density. Deep depressurization by dropping the pressure below the quadruple point is recognized as a promising exploitation method. However, the impact of ice formation on NGHs dissociation within depressurization is still controversial. Thus, we examine the dissociative behavior of NGHs at low temperature below the quadruple point using a high-pressure reactor. It primarily focuses on how ice formation affects heat and mass transfer, as well as the kinetics of hydrate dissociation. The results indicate that during the hydrate dissociation process, liquid water initially transforms into metastable supercooled water, which then transitions to solid ice under external disturbance. Ice nucleation predominantly occurs in two locations: within the free water phase and on the surface of hydrate particles. A double-edged effect of ice on NGHs dissociation is observed: the latent heat released by ice nucleation and generation could accelerate the hydrate breakdown (positive effect), while the decrease in permeability along with the self-preservation effect from ice formation tends to inhibit the NGHs dissolution (negative effect). In addition, a higher pressure drawdown rate can accelerate both ice nucleation and formation, which in turn shortens the freezing induction time. The increase of water saturation (<em>S</em>_<em>A</em>) and the decrease of hydrate saturation (<em>S</em>_<em>H</em>) can significantly reduce the mining time and strengthen both the hydrate dissociation rate (<em>Q</em>_<em>H</em>) and gas production rate (<em>Q</em>_<em>P</em>). Therefore, hydrate sediments with higher <em>S</em>_<em>A</em> or lower <em>S</em>_<em>H</em> are more conductive to gas recovery of low-temperature NGHs deposits in permafrost regions.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205468"},"PeriodicalIF":0.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142534536","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":"Artificial general intelligence for the upstream geoenergy industry: A review","authors":"Jimmy Xuekai Li,&nbsp;Tiancheng Zhang,&nbsp;Yiran Zhu,&nbsp;Zhongwei Chen","doi":"10.1016/j.jgsce.2024.205469","DOIUrl":"10.1016/j.jgsce.2024.205469","url":null,"abstract":"<div><div>Artificial General Intelligence (AGI) is set to profoundly impact the traditional upstream geoenergy industry (i.e., geothermal energy, oil and gas industry) by introducing unprecedented efficiencies and innovations. This paper explores AGI's foundational principles and its transformative applications, particularly focusing on the advancements brought about by large language models (LLMs) and extensive computer vision systems in the upstream sectors of the industry. The integration of Artificial Intelligence (AI) has already begun reshaping the upstream geoenergy landscape, offering enhancements in production optimization, downtime reduction, safety improvements, and advancements in exploration and drilling techniques. These technologies streamline logistics, minimize maintenance costs, automate monotonous tasks, refine decision-making processes, foster team collaboration, and amplify profitability through error reduction and actionable insights extraction. Despite these advancements, the deployment of AI technologies faces challenges, including the necessity for skilled professionals for implementation and the limitations of model training on constrained datasets, which affects the models' adaptability across different contexts. The advent of generative AI, exemplified by innovations like ChatGPT and the Segment Anything Model (SAM), heralds a new era of high-density innovation. These developments highlight a shift towards natural language interfaces and domain-knowledge-driven AI, promising more accessible and tailored solutions for the upstream geoenergy industry. This review articulates the vast potential AGI holds for tackling complex operational challenges within the upstream geoenergy industry, requiring near-human levels of intelligence. We discussed the promising applications, the hurdles of large-scale AGI model deployment, and the necessity for domain-specific knowledge in maximizing the benefits of these technologies.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205469"},"PeriodicalIF":0.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic mechanism and exploration progress of global deep alkane gases and small molecule gases (H2, He)","authors":"Guangyou Zhu ,&nbsp;Jiakai Hou ,&nbsp;Ziguang Zhu ,&nbsp;Zhiqi Yu ,&nbsp;Wenqi Li ,&nbsp;Tingting Li","doi":"10.1016/j.jgsce.2024.205467","DOIUrl":"10.1016/j.jgsce.2024.205467","url":null,"abstract":"<div><div>From the perspective of global oil and gas exploration trends, deep to ultra-deep gas exploration has emerged as a focal point in the past decade, shaping the future landscape of fossil energy exploration. Specifically, China has undertaken oil and gas exploration ventures reaching depths of 10,000 m, drawing significant attention to the genesis of gas accumulation at such extreme depths. An analysis of crucial geological factors including basin formation, hydrocarbon generation, storage and accumulation reveals that kerogen cracking gas, crude oil cracking gas, and coal cracking gas served as vital gas sources for ultra-deep paraffin gas in highly over-mature oil-bearing basins, establishing a model for the formation, evolution, and accumulation of natural gas. With the continuous expansion of hydrocarbon genesis theory and the increasing global demand for clean energy, hydrogen, as an important link between inorganic and organic hydrocarbon generation theory, and as a promising clean energy, has gradually aroused extensive attention in the academic community. The genetic types of natural hydrogen are mainly generated from inorganic genetic mechanisms, including earth degassing, water-rock interaction, and water radiolysis. The lithology of the reservoir and the sealing property of the cap layer control the accumulation of natural hydrogen, with the salt-rock cap layer beneficial to the large-scale preservation of natural hydrogen reservoir. Helium, as a constituent resource of natural gas, represents the primary target for exploration among deep small molecule gases. Helium within natural gas reservoirs can be categorized into atmospheric, crust-source and mantle-source varieties based on their origins. Helium source rocks exhibit significant disparities in helium generation capacity attributed to variations in rock types, mineral compositions, and ages, resulting in a relatively complex mechanism governing helium reservoir release, migration and accumulation. Typically, helium-rich gas reservoirs lack optimal cap sealing performance, as excessive sealing inhibits the formation of pressure relief conduits, thereby impeding the supply of helium-rich fluid to the reservoir. Through an analysis of genetic types, formation and evolution models, and reservoir preservation mechanisms pertinent to deep alkane gases and small molecule gases, it is revealed that the large-scale pool-forming geologic units and giant hydrocarbon enrichment zones in ultra-deep strata are key and promising prospects for delivering successive discoveries, and the energy significance and development trend of natural hydrogen and helium in the future were pointed out, in order to provide references for promoting the transition from high carbon to low carbon and carbon-free energy in the energy field.</div></div>","PeriodicalId":100568,"journal":{"name":"Gas Science and Engineering","volume":"131 ","pages":"Article 205467"},"PeriodicalIF":0.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418696","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}