This work presents the first evaluation of biochar's triple functions in enhancing in-situ hydrogen (H2) production via electromagnetic (EM) heating. The role of biochar as an energy enhancer, catalyst, and facilitator is identified and systematically investigated in the presence of reservoir rocks. Specifically, experiments show that incorporating 10 wt% biochar into sandstone significantly improves the EM-heating efficiency of the rock, reducing up to 76.1% input power when compared to non-biochar samples. This composite also produces the highest H2 yield compared with either pure rock or pure biochar, achieving a maximum H2 concentration of 81% with an optimal energy consumption of 2.16 MJ/g H2, indicating a synergistic effect between reservoir rocks and biochar. Parametric analyses demonstrate that smaller particle sizes are favorable for enhanced H2 production. The mechanisms of water-biochar/carbon interactions are examined in carbon-containing rocks using two types of water (H2O and D2O), suggesting that different carbon types result in distinct gas compositions in the resulting H2-rich gas. We further investigate that biochar not only facilitates hydrogen generation but also improves the catalytic activity in the presence of water. These findings highlight biochar's multifunctional role in enhancing EM energy absorption, catalyzing CH4-to-H2 conversion, and facilitating H2 generation, indicating its strong potential for efficient in-situ H2 production from natural gas reservoirs.

In the shale oil industry, nearly 90 % of reserves remain unrecovered in depleted reservoirs due to geological constraints and technological limitations. Recent studies have demonstrated that electromagnetic (EM) heating can effectively initiate the conversion of such unrecovered hydrocarbons into high-purity hydrogen in the presence of reservoir rocks, enabling direct and clean hydrogen extraction from shale reservoirs. However, the role of water-commonly present in shale formations-has been largely overlooked in prior research. This study quantitatively investigates the mechanism of water's contribution to in-situ hydrogen during shale oil conversion under EM heating. Experimental observations reveal that when water and oil are present at a 1:1 wt ratio, water not only doubles the hydrogen yield via water-hydrocarbon reactions but also increases hydrogen purity to around 50 % by promoting the conversion of short-chain hydrocarbons into hydrogen. Isotopic tracing using deuterated water (D2O) reveals that 61.5 % of the produced hydrogen originates from shale oil, while the remaining 38.5 % is associated with water. In addition to water-hydrocarbon reactions, experiments confirm that water actively participates in secondary reactions (i.e., coke gasification and water-gas shift reaction), producing extra hydrogen and reducing coke/carbon accumulation in reservoir rocks. This work highlights water's dual function as both a direct hydrogen source and an effective hydrogen facilitator, advancing the technological readiness of in-situ hydrogen production from water-bearing shale oil reservoirs.

In-situ conversion of subsurface hydrocarbons via electromagnetic(EM)heating has emerged as a promising technology for producing carbon-zero and affordable hydrogen(H2)directly from natural gas reservoirs.However,the reaction pathways and role of water as an additional hydrogen donor in EM-assisted methane-to-hydrogen(CH4-to-H2)conversion are poorly understood.Herein,we employ a combination of lab-scale EM-heating experiments and reaction modeling analyses to unravel reaction pathways and elucidate water's role in enhancing hydrogen production.The labelled hydrogen isotope of deuterium oxide(D2O)is used to trace the sources of hydrogen.The results show that water signifi-cantly boosts hydrogen yield via coke gasification at around 400 ℃ and steam methane reforming(SMR)reaction at over 600 ℃ in the presence of sandstone.Water-gas shift reaction exhibits a minor impact on this enhancement.Reaction mechanism analyses reveal that the involvement of water can ini-tiate auto-catalytic loop reactions with methane,which not only generates extra hydrogen but also pro-duces OH radicals that enhance the reactants'reactivity.This work provides crucial insights into the reaction mechanisms involved in water-carbon-methane interactions and underscores water's potential as a hydrogen donor for in-situ hydrogen production from natural gas reservoirs.It also addresses the challenges related to carbon deposition and in-situ catalyst regeneration during EM heating,thus derisk-ing this technology and laying a foundation for future pilots.

Over the past two decades, shale oil has emerged as a major contributor to the global oil market. Nevertheless, approximately 90% of shale oil resources remain unrecovered due to geological constraints and technological limitations, resulting in low overall energy efficiency. Recent studies have demonstrated that electromagnetic (EM) heating can effectively initiate the in-situ conversion of shale oil into hydrogen, enabling both the extraction of such unrecovered hydrocarbons and the direct production of high-purity hydrogen within shale reservoirs. However, the role of water—commonly present in shale formations—has been largely overlooked in prior research. This study quantitatively examines the impact of water on shale oil conversion to in-situ hydrogen under EM heating. Experimental results show that in oil-water mixtures with a 1:1 weight ratio, water not only doubles hydrogen yield but also increases hydrogen purity to 50% by promoting the conversion of short-chain hydrocarbons to hydrogen. Isotopic tracing using deuterium oxide (D2O) reveals that 61.5% of the produced hydrogen originates from shale oil, while the remaining 38.5% is associated with water. This indicates that water plays a critical role in secondary reactions (i.e., coke gasification and water-gas shift reactions) to generate extra hydrogen and reduce coke/carbon buildup within the reservoir, potentially improving borehole permeability and enabling sustained hydrogen production over time. Overall, this study provides crucial insights into water's dual role as both a hydrogen source and a reaction facilitator, advancing the technological readiness of in-situ hydrogen production from water-bearing shale oil reservoirs.

Electromagnetic (EM)-assisted catalytic heating for in-situ hydrogen generation directly from petroleum reservoirs is an emerging method for decarbonizing petroleum industry and facilitating energy transition. Lab-scale experiments have shown that hydrogen generated from methane cracking in the presence of sandstone via EM heating can reach up to a concentration of 91 mol.% at 668 degrees C. However, the role of various minerals in reservoir rocks during this process remains poorly understood. This study aims to decipher the natural catalytic effects of minerals of reservoir rocks, such as quartz, kaolinite, illite, chlorite, etc., in catalyzing methane conversion to hydrogen under EM irradiation. Our findings demonstrate that kaolinite exhibits the strongest catalytic activity, starting to generate hydrogen at 331 degrees C and achieving a 73% methane conversion at 450 degrees C, while chlorite and albite also showing notable activity with hydrogen being generated below 500 degrees C. Furthermore, this study quantifies the catalytic contributions of metal oxides, Na+ in albite, Fe2+ and Mg2+ in chlorite and illite, and Al3+ in kaolinite, in promoting methane conversion to hydrogen. By deciphering the catalytic role of minerals and metal oxides, this research offers crucial insights for future optimization of field-scale H2 production from gas reservoir by leveraging the minerals of reservoir rocks as natural catalysts.

The global push for sustainable energy solutions has highlighted the importance of producing carbon-zero hydrogen (H2) directly from petroleum reservoirs. In-situ combustion gasification (ISCG) presents a groundbreaking method to harness the potential of heavy oil reserves for clean hydrogen production. Although simulations have demonstrated the considerable promise of ISCG, the key reactions controlling hydrogen generation require experimental validation, and the underlying mechanisms remain largely unexplored. This research aims to describe the chemical reactions and mechanisms responsible for hydrogen generation during the ISCG of heavy oil. Using a specially designed kinetic cell, we conducted combustion and gasification experiments with heavy oil and coke. The findings revealed that clay minerals in the reservoir sand act as catalysts in the oxidation reactions of heavy oil by shifting reactions to lower temperatures by approximately 20 degrees C. Hydrogen production began at 450 degrees C and peaked at 900 degrees C, with coke gasification and the water-gas shift reaction being the primary mechanisms. Additionally, methane was produced due to hydrogen consumption via methanation reactions, and minerals in the reservoir sands were found to inhibit hydrogen production by increasing hydrogen consumption and methane generation at temperatures above 800 degrees C. Controlling the reservoir temperature within an optimal range between 450 and 800 degrees C can enhance hydrogen generation by managing the process mechanisms. This study provides a detailed examination of the ISCG process for heavy oil, paving the way for future development of kinetic models to simulate hydrogen production through ISCG. It also emphasizes the significance of mechanistic control in enhancing hydrogen generation and suppressing hydrogen consumption reactions.

Employing electromagnetic(EM)-assisted catalytic heating to produce hydrogen (H 2 ) directly from petroleum reservoirs is an emerging technology for decarbonizing fossil fuel industry. Transforming hydrocarbons to clean H 2 in situ will enable pure hydrogen extraction to surface while simultaneously sequestering carbon underground with the assistance of downhole hydrogen membrane separation technology. Here, we aim to characterize the role of shale rocks in enhancing EM heating and catalyzing shale oil conversion to hydrogen as natural catalysts under EM irradiation. Flow -through experiments are well designed and conducted in a customized microwave reactor system. We also identified for the first time that shale rocks exhibit a " thermal runaway " (TR) phenomenon which occurs at a temperature of 280 degrees C. After TR happens, the energy needed for heating shale samples to a high enough temperature is significantly reduced under EM irradiation. Further, we identified that metal -rich minerals in shale rocks play an evident natural catalytic effect on shale oil conversion to hydrogen. As a result, hydrogen with a percentage of 1 mol.% starts to be generated at a measured temperature of 253 - 421 degrees C in the presence of shale rocks and is a dominant gas in the generated gas products at high temperatures. The highest production rate and concentration of H 2 gas are 178 sccm and 77 mol.% from the conversion of 0.4 g of shale oil, respectively. Importantly, CO 2 generated during the process is negligible. This work lays a foundation for leveraging the abundant shale rocks and their natural catalytic effect for more efficient, cost-effective, in -situ hydrogen production directly from shale reservoir via the EM -assisted catalytic heating technology we recently proposed.

To address the escalating demands for decarbonization in the petroleum industry, a carbon-zero technology, known as in-situ hydrogen (H2) 2 ) production via electromagnetic (EM)-assisted catalytic heating, has recently been proposed for generating and extracting clean H2 2 directly from petroleum reservoirs. Although preliminary techno-economic analyses show significant potential of this emerging technology for clean and affordable hydrogen, the fundamentals of natural gas conversion to H2 2 in the presence of reservoir rocks are poorly understood. In this study, we explore the synergy between sandstone and artificial iron-based catalysts in enhancing in-situ H2 2 production from methane (CH4) 4 ) cracking under EM irradiation. The dynamic behaviors of sandstone under EM heating are comprehensively investigated, including its thermal behaviors, thermal runaway (TR) phenomenon, gas generation during TR, and energy consumption. We found that sandstone demonstrates an evident natural catalytic effect for promoting CH4 4 conversion to H2, 2 , enabling H2 2 production starting at about 394 degrees C. The natural catalytic role of iron minerals in sandstone is elucidated using various advanced characterization techniques. Remarkably, when adding iron catalysts into the sandstone, the highest H2 2 concentration and CH4 4 conversion reaches 91 mol.% and 80%, respectively, at a temperature of 666 degrees C, while they are 50 mol. % and 35%, respectively, for the sample consisting of iron catalysts and quartz at the same level of temperature. This result indicates a strong iron-sandstone synergy and a potential to stimulate H2 2 production by leveraging this synergy. Throughout the experimental process, the generation of carbon oxides (CO and CO2) 2 ) is negligible. These findings pave a pathway towards future pilot for carbon-zero in-situ H2 2 production from sandstone gas reservoirs.

Electromagnetic(EM)-assisted catalytic heating presents a novel method for in-situ hydrogen production from petroleum reservoirs. This study delves into the interaction between electromagnetic waves and reservoir rocks, characterizing the fundamentals behind thermal runaway (TR) phenomenon in sandstones and shales. Utilizing a custom microwave reactor and advanced analysis techniques, we identify the microwave-induced thermal runaway phenomenon in San Saba sandstone rocks at - 568 degrees C and Mancos shale rocks at - 253 degrees C, emphasizing the role of mineral, elemental compositions, and dielectric properties in these differences. We also identified that chlorite, albite, and illite are major contributors to thermal runaway and the significant reduction in power required for reheating rocks, saving 50.0-66.7% for sandstone and 64.0-80.0% for shale. This work contributes new insights into the occurrence and mechanisms of thermal runaway in reservoir rocks, therefore providing an efficient way for enhancing heating efficiency and reducing energy input for in-situ hydrogen production. This research further de-risks the emerging technology for in-situ hydrogen production from petroleum reservoirs via electromagnetic-assisted catalytic heating.

Abstract Recently, a subsurface technology of in-situ hydrogen production using electromagnetic (EM) heating shows great potential for extracting clean hydrogen directly from natural gas reservoirs. However, critical knowledge gaps persist, particularly in technical assessments. This study addresses these gaps by evaluating energy efficiency, techno-economic viability, and greenhouse gas (GHG) emissions throughout the process. We analyze the system energy efficiency under various experimental conditions using sandstone and synthetic catalysts. The results highlight the potential for field improvements through the optimization of catalysts and methane flow rates. Techno-economic analysis (TEA), based on a developed reservoir-scale model, indicates hydrogen production cost can be potentially as low as $0.86/kg with the integration of renewable energy. Key cost drivers include membrane expenses and EM-heating electricity for hydrogen production. Life cycle assessment (LCA) indicates that methane pyrolysis in gas reservoirs does not generate GHG emissions throughout its life cycle. However, GHG emissions associated with electricity use (i.e., EM heating) in the process should be considered. Moreover, the technology's eligibility for Section 45 V of Inflation Reduction Act (IRA 45 V) clean hydrogen credits is contingent upon the source of electricity used. And the qualification for the credits depends on the proportion of renewable energy in the electricity consumption mix. This study provides insights into efficiency optimization, cost competitiveness, and environmental considerations for in-situ hydrogen production from gas reservoirs using EM heating.

Hydrogen (H2) is increasingly recognized worldwide as a pivotal, clean energy carrier essential for decarbonizing various sectors, including transportation, power generation, and fuel-intensive industries. While hydrogen can be produced from diverse sources, the most common method is steam methane reforming, which however generates 9-10 kg carbon dioxide (CO2)/kg H2. Considering the dominant share of fossil fuels in global energy consumption, new technologies are imperative to expedite the transition to a cleaner hydrogen-based energy source. An emerging alternative for hydrogen production is to generate it directly from petroleum reservoirs via the insitu combustion gasification technology. This novel approach produces hydrogen by triggering reactions between hydrocarbons, rocks, and water within petroleum reservoirs. Hydrogen-selective membranes are used to separate the generated hydrogen with all undesired gases being sequestrated within the reservoir, making it a carbon-zero technology. With increasing experimental and simulation work, this technology shows promising potential for large-scale hydrogen generation in an environmentally friendly manner. This paper identifies the technological potential and scientific challenges, delves into the fundamentals of the process, and discusses its efficiency, costeffectiveness, and environmental benefits. Moreover, it highlights the importance and key aspects involved in fundamental fluid chemistry, reservoir geology, reactions, and engineering design to enhance the development and deployment of this technology. This paper aims to catalyze advancements of this new, clean technology and accelerate the transition from a fossil fuel-based economy to a carbon-zero economy.

Steam methane reforming (SMR) generates about 95% of hydrogen (H2) in the U.S. using natural gas as a main feedstock. However, this technology also generates a large amount of carbon dioxide (CO2), a major greenhouse gas causing global warming. Carbon capture and storage (CCS) technique is required, but the cost and safety of storing CO2 underground are a concern. Here we propose a new approach using microwave/electromagnetic irradiation to produce clean hydrogen from unrecovered hydrocarbons within petroleum reservoirs. Solid carbon or CO2 produced during this process will be simultaneously sequestrated underground without involving CCS. In this paper, we perform a series of experiments to investigate the in-situ hydrogen production from shale gas (methane) conversion by passing a methane stream through a packed shale rock sample heated by microwave. We found that methane conversion was significantly enhanced in the presence of Fe and Fe3O4 particles as catalysts, with a conversion of 40.5% and 100% at reaction temperature of 500 degrees C and 600 degrees C, respectively. Methane conversion is promoted at a lower reaction temperature by the catalytic effect of minerals in shale. Additionally, the influences of catalysts, shale rock, and methane flow rate are characterized.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Steam methane reforming (SMR) technology generates about 95% hydrogen (H2) in the United States using natural gas as a main feedstock. While hydrogen is clean, the process of hydrogen generation via SMR is not, as it emits about 10 times more carbon dioxide (CO2) than hydrogen. The CO2 has to be captured and sequestrated in reservoirs or aquifer systems, which is costly. A revolutionary approach is to generate and extract hydrogen directly from petroleum reservoirs by taking advantage of the abundant unrecovered hydrocarbons in reservoirs. This approach does not involve natural gas production, transportation, or refinery. Meanwhile, the CO2, if generated, will be sequestrated simultaneously in reservoirs without being produced to surface. This approach is therefore potentially low cost and environmentally friendly. In this paper, we propose to use microwave-assisted catalytic heating to enhance methane conversion to hydrogen within shale gas reservoirs. To validate this concept, we conducted a series of experiments to crack methane streams flowing through shale rock samples and powders in a microwave reactor. With silicon carbide (SiC) as the microwave receptor, the temperature of shale samples can quickly reach to above 700 °. The methane conversion efficiency is up to 40.5% and 100% in the presence of Fe and Fe3O4 catalysts at the measured temperature of 500° and 600 °, respectively. Interestingly, the presence of shale is favorable for methane cracking at a relatively lower temperature compared to the case with the same weight percentage of SiO2 in heated samples. The thermal decomposition of carbonate in shale rocks also benefits the improvement of permeability of shale. The influences of different shale weight ratios and methane flow rates are also investigated.

针对顺北油田井筒举升过程中,随温度逐步降低,沥青质及蜡质颗粒逐渐聚集、沉淀析出的问题,以顺丁烯二酸酐和二乙醇胺为原料,采用"伪一锅法"合成了端羟基超支化不饱和聚酰胺-胺,并对其末端活性基团进行改性,合成了一种新型超支化表面活性剂(HMPS).采用红外光谱、核磁、差热-热重、元素分析及凝胶渗透色谱对产物结构进行了表征.将HMPS与重芳烃油、异戊醇按一定比例配制成沥青分散剂,该分散剂对顺北油田井筒取样沥青具有良好的溶解分散性,在50、70和90℃条件下,10 g沥青质分散剂对2 g沥青的溶解率依次为85％、99％和100％.

为有效利用棉浆黑液、减少环境污染,以碱法棉浆黑液、苯酚、甲醛和聚丙烯酰胺为原料,通过水热法制备了黑液-酚醛复合凝胶,通过红外光谱、热重分析和扫描电镜对凝胶结构进行了表征,研究了苯酚加量对凝胶的影响,评价了凝胶的耐盐性、耐酸碱腐蚀性和封堵效果.结果表明,黑液-酚醛复合凝胶网络致密紧凑,热分解温度为200℃.苯酚加量为2％～4％的凝胶的成胶时间为24～14 h,含水率为72％～75％,吸水倍数为3.60％～3.92％.该凝胶具有黏度低、易泵入的优点,且具有良好的耐盐、耐酸碱性能.凝胶的封堵效果良好,对人工模拟岩心的封堵率大于99％.利用棉短绒黑液制备油田堵剂,不仅可以改善黑液污染,还可降低稠油开采成本.

以强混酸处理的新疆黑山煤为部分碳源,通过静电纺丝法成功制备了具有丰富含氧官能团的柔性炭纤维(CCNFs).将该材料作为锂离子电池的自支撑负极,煤的加入量为0.5 g的炭纤维样品0.5-CCNFs展现出优异的循环稳定性,电池在电流密度为0.5 A·g-1下,循环1 000圈后,比容量高达524.1 mAh·g-1.在较大的电流密度(1 A·g-1)下,其首次比容量为719.1 mAh·g-1,充放电循环1 000圈后,其比容量仍高达331.8 mAh·g-1.

Vacuum heat insulating tubing is an important wellbore heat insulating facility for heavy oil thermal recovery at present. Its heat insulating performance directly affects the thermal recovery efficiency. The research on the heat insulating system of vacuum heat insulating tubing is of great significance to improve and improve the heat insulating performance and enhance the thermal recovery of heavy oil. This paper summarizes and analyses the current research status of vacuum insulated tubing insulation system. It elaborates the insulation structure, insulation materials, annular air charging and vacuum pumping, insulation coating and so on. It provides reference and reference for the future research of vacuum insulated tubing.

以塔河常渣(THAR)为研究对象,在不同的反应温度及反应时间下,进行减黏裂化反应,考察不同反应条件对产物分布及减黏油性质的影响.研究结果表明,随反应温度和反应时间的增加,减黏油的黏度逐渐降低,生焦率呈上升趋势.塔河常渣的沥青质含量极高,即使在较缓和的操作条件下,依然易产生大量焦炭,影响其运输.为减小生焦量,本文提出供氢剂抑焦、供氢催化改质抑焦、超临界流体分散等3种方案,并进行对比分析.研究发现,供氢剂四氢萘只有在加压状态下呈现液相时才能起到供氢作用,其生焦量随着四氢萘加入量的增加而减少.油酸及环烷酸钴具有催化四氢萘的供氢作用,其加入能进一步降低生焦.甲苯在低压状态下对抑制体系生焦不明显,当压力升高到超临界压力后,超临界甲苯由于具有溶解及分散重油的作用,可减少缩合反应,使生焦总量降低.

Purpose – Casing damage problems are increasingly prominent in oil fields, most of which were caused by casing external squeezing loads. The traditional calculation method of casing external squeezing loads is not very accurate now, especially in complex formation. The purpose of this paper is to propose a new calculation method to solve the problem of actual casing loads under above conditions. Design/methodology/approach – Based on Lame’s model of elastic mechanics, a new calculation method of casing external squeezing loads is deduced. Comprehensive influence laws of the loads which caused by in-situ stress, internal pressure, formation parameters, cement annulus parameters and casing parameters are analyzed. Findings – The paper provides a new calculation method of casing external squeezing loads, by which the dispersion effect of internal liquid pressure caused by casing wall material is eliminated. The main influence factors of casing external squeezing loads are in-situ stress and formation elastic modulus. Research limitations/implications – The model and boundary conditions used in the paper is based on elastic mechanics. The accuracy of the calculation results depends on the quality and accuracy of the input formation parameters. Originality/value – This paper proposes a new method to calculate casing external squeezing loads. And compared with traditional methods, this method is more practical.