Article
Energy & Fuels
Yilei Song, Zhaojie Song, Haiwei Zeng, Chunlei Tai, Xuya Chang
Summary: This study compared the enhanced oil recovery (EOR) performance of N-2 and CO2 Huff-n-puff methods at the pore level using nuclear magnetic resonance (NMR) technology. The results showed that both N-2 and CO2 Huff-n-puff methods improved tight oil recovery, with CO2 Huff-n-puff exhibiting better performance. The NMR transverse relaxation time (T-2) spectrum indicated that CO2 Huff-n-puff was more effective in enhancing oil recovery in large pores compared to N-2 Huff-n-puff. However, the conclusion should be further validated due to the potential error of NMR technology in measuring oil recovery in specific pores.
Article
Energy & Fuels
Chao-Fan Zhu, Wei Guo, You-Ping Wang, Ya-Jun Li, Hou-Jian Gong, Long Xu, Ming-Zhe Dong
Summary: This study investigates the impact of fractures and kerogen in shale reservoirs on oil recovery during CO2 huff-n-puff operations. It reveals that rock properties play a significant role in determining recovery factors and CO2 usage efficiency in shale and sandstone formations. Optimal injection pressures and CO2 injection volumes are identified for enhanced oil recovery in fractured shale reservoirs.
Article
Energy & Fuels
Mukhtar Elturki, Abdulmohsin Imqam
Summary: This study investigated the effects of cyclic N-2 injection on oil recovery and asphaltene precipitation in shale cores. The results showed that cyclic N-2 injection increased oil recovery but worsened the wettability of the cores, leading to asphaltene deposition and pore plugging.
Article
Energy & Fuels
Faisal Altawati, Hossein Emadi, Rayan Khalil, Lloyd Heinze, Habib Menouar
Summary: This study investigates the feasibility of using liquid nitrogen and N-2, CO2 huff-n-puff injections to improve the oil recovery factor (RF) of unconventional reservoirs. The results show that LN2-assisted N-2 and/or CO2 huff-n-puff injections can improve the oil RF, particularly for samples with low permeability.
Article
Thermodynamics
Xiang Zhou, Xiuluan Li, Dehuang Shen, Lanxiang Shi, Zhien Zhang, Xinge Sun, Qi Jiang
Summary: This study investigated heavy oil production performance using the CO2 huff-n-puff process and the potential of CO2 storage in abundant reservoirs through experimental and mathematical studies. The results showed that increasing injection pressure and optimizing pressure depletion rates can improve heavy oil recovery factor, and an equation has been developed to predict the relationship between heavy oil and gas production. The significant influences on CO2 capacity were found to be CO2 stored in available space and dissolved into remaining heavy oil.
Article
Energy & Fuels
Do Yoon Moh, Hongwei Zhang, Shihao Wang, Xiaolong Yin, Rui Qiao
Summary: The study investigates the soaking step of CO2 Huff-n-Puff in a single, 4 nm-wide calcite pore using molecular dynamics simulations. The results show that CO2 molecules can be adsorbed on pore walls and diffuse along the walls or into the pore's interior as free molecules. The movement of adsorbed and free CO2 molecules inside the pore obeys a specific scaling law, highlighting the importance of surface adsorption in the storage and transport of CO2 in unconventional oil reservoirs.
Article
Energy & Fuels
Mukhtar Elturki, Abdulmohsin Imqam
Summary: It is essential to investigate gas injection methods to produce the trapped oil in unconventional resources. However, the injection process can cause asphaltene depositions inside the reservoir, leading to plugging of pores and oil recovery reduction. This study examines the significance of CO2 injection in oil recovery and identifies the critical parameters that could impact the effectiveness of CO2 huff-n-puff operation in unconventional formations.
Article
Energy & Fuels
Xiaofei Xiong, J. J. Sheng, Xiaofeng Wu, Jianghua Qin
Summary: The study demonstrates that conducting foam-assisted nitrogen huff-n-puff experiments in fractured shale cores can inhibit gas channeling, extend gas channeling time, and expand the swept area, thereby helping to improve oil recovery in shale reservoirs.
Article
Engineering, Chemical
Tong Wang, Bo Xu, Yatong Chen, Jian Wang
Summary: In this study, CO2 huff-n-puff laboratory experiments were conducted on the Chang 7 shale oil reservoir, and the utilization of microscopic pore fluid in short samples was investigated using the NMR technique. The seven controlling factors and their recovery-enhancing mechanisms of CO2 huff-n-puff were analyzed and discussed. The experimental results showed that the cumulative recovery increased with the number of huff-n-puff cycles, but the degree of cycle recovery decreased due to the limitation of the production differential pressure. Increasing the minimum depletion pressure and gas injection amount achieved a significant increase in recovery after CO2 mixed-phase drive. The pressure depletion rate was found to be the main factor affecting the CO2 huff-n-puff effect in shale.
Article
Energy & Fuels
Alsu Garipova, Elena Mukhina, Alexander Cheremisin, Margarita Spivakova, Anton Kasyanenko, Alexey Cheremisin
Summary: This article presents a numerical simulation of hydrocarbon gas injection into a horizontal well with multiple hydraulic fractures in the Bazhenov shale oil formation in Western Siberia. It is the first complex field-scale study of gas injection for this formation and explores the effects of different operating parameters and fracture models on oil recovery. The results show a significant increase in oil recovery, ranging from 34% to 117%, depending on the fracture model and gas injection method.
Article
Engineering, Chemical
Qian Sun, Aabiskar Bhusal, Na Zhang, Kapil Adhikari
Summary: In this study, a new method was proposed to estimate the MMP of shale oil/CO2 systems using huff-n-puff molecular dynamics simulations. The obtained results were in good agreement with experimental data. The oil recovery increased with the rise of reservoir temperature and slit height, but the MMP inside the nanopore was lower than the bulk counterpart due to confinement effect. CO2 huff-n-puff has the benefits of oil recovery and carbon sequestration.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Energy & Fuels
Zhengdong Lei, Yishan Liu, Rui Wang, Lei Li, Yuqi Liu, Yuanqing Zhang
Summary: This paper conducts a microfluidic experiment to reveal the microscopic mechanism of CO2 and crude oil after contact at the microscale, and quantifies the change characteristics of the remaining oil occurrence state after CO2 injection. The results show that CO2 mainly produces crude oil in macropores and microfractures, improves oil mobility through diffusion dissolution, and the driving force is dissolved gas in depressurization production. The mechanisms for CO2 to improve shale oil include extraction and dissolution expansion.
Article
Energy & Fuels
Yukun Chen, Dongming Zhi, Jianhua Qin, Ping Song, Hui Zhao, Fuyong Wang
Summary: This study investigates the methods for enhancing shale oil recovery rates in the Jimsar sag, Junggar Basin, NW China. The results show that CO2 huff and puff method and surfactant imbibition method have a positive effect on improving oil recovery, while fracturing liquid imbibition method without surfactant performs poorly. Surfactants can enhance spontaneous imbibition oil recovery by approximately 18% more in the type II and III shale formations.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
M. Akbarabadi, A. H. Alizadeh, M. Piri, N. Nagarajan
Summary: The significant amount of gas produced from unconventional reservoirs in the US in recent years has created an opportunity for using low-cost gas in enhanced oil recovery projects. Experimental and numerical studies have shown the great potential of using produced gas as an injectant for enhanced oil recovery from tight shale resources. The objective of this study is to investigate the feasibility of produced gas huff-and-puff operations in a major oil-producing shale formation in North America.
Article
Chemistry, Multidisciplinary
Shuai Li, Shenglai Yang, Wengang Dong, Kun Yang, Bin Shen, Jiayi Yu
Summary: This study investigates the impact of different water injection pressures and methods on tight volcanic oil reservoirs, revealing the oil production law and mechanism of water injection. The results show that the water injection method significantly affects the recovery factor of tight volcanic oil reservoirs.
Article
Energy & Fuels
Xiaoyu Hou, James J. Sheng
Summary: A novel spontaneous emulsification (SE) system with a low concentration of alkali was developed in this study. The EOR mechanism of the SE system was revealed using NMR and MRI, and the system effectively avoided scale formation in low-permeability reservoirs.
Article
Energy & Fuels
James J. Sheng
Summary: Energized fluid fracturing utilizing the high compressibility of fluids and their compatibility with the formation facilitates flow back and oil/gas production. However, the potential for enhanced oil recovery from such fluid fracturing is limited, as indicated by field tests and simulation models. Further research and testing are needed to fully understand the capabilities and limitations of energized fluid fracturing in EOR processes.
Article
Energy & Fuels
Weiyu Tang, James J. Sheng
Summary: This study examines the effects of different gas injection modes on oil recovery in tight formations with varying permeabilities through experiments and numerical simulations. Results show that gas flooding is more efficient at higher permeabilities, while huff-n-puff injection is superior at lower permeabilities.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Zijian Wei, J. J. Sheng
Summary: Improving permeability is crucial for enhancing oil and gas recovery in ultra-low permeability reservoirs. This study investigates the temperature and stress sensitivity of permeability using heating treatment and real-time measurement on cores from different reservoirs. The results show that the permeability increases with temperature and stress, with different mechanisms observed in different rocks.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Nelson R. K. Tatsipie, James J. Sheng
Summary: This study proposes a method to predict oil production of a stimulated horizontal well using an artificial neural network model, and explores the effects of various well completion and reservoir parameters on oil production through sensitivity analysis.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Lingfeng Yang, James J. Sheng
Summary: The air injection process (AIP) is an enhanced oil recovery method that has been used for decades. This study investigates the oxidation of crude oil under adiabatic and high-pressure conditions, with the presence of different mineral particles. The results show that iron minerals have a catalytic effect on the high-temperature oxidation of crude oil, while pyrite cannot catalyze crude oil oxidation under limited oxygen conditions.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Petroleum
Hao Zhang, James J. Sheng
Summary: This article proposes a novel framework for optimizing the hydraulically fractured well in shale-gas reservoirs with geological uncertainty. It also introduces a hybrid multiobjective particle-swarm optimization algorithm and a Gaussian-process Kriging model as a surrogate model. By applying these methods, the efficiency and accuracy of hydraulic fracturing design can be improved.
Article
Energy & Fuels
Kerui Liu, James J. Sheng
Summary: This study investigates the role of clay swelling in shale fracturing by combining fracture generation, permeability change, and stress anisotropy. The results show that clay swelling impacts fracture generation through the generation of micro fractures and weakening the mechanical strength of shales. Moreover, clay swelling has a positive effect on the recovery of samples' permeability by increasing the width of existing fractures.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Zesen Peng, J. Sheng
Summary: In this study, the CO2 diffusion coefficient of shale under reservoir conditions was determined in the laboratory, and its contribution to enhanced oil recovery (EOR) during the huff-n-puff process was evaluated using a reservoir numerical model. The results showed that including CO2 diffusion in the model while reducing fracture spacing and increasing fracture half-length promoted the CO2 diffusion effect. Additionally, slower injection rates and shorter injection times were found to enhance the contribution of CO2 diffusion to EOR.
Article
Energy & Fuels
James J. Sheng
Summary: This article discusses the flow back of aqueous fluid during hydraulic fracturing and proposes a hypothesis that it is controlled by viscous displacement and capillary imbibition mechanisms. The hypothesis is verified through simulation models, indicating that the effectiveness of immediate flow back or shut-in depends on reservoir and operation conditions.
PETROLEUM SCIENCE AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Xiaoyu Hou, James J. Sheng
Summary: Experimental and simulation studies have shown mixed results on the effects of shut-in and interfacial tension (IFT) reduction in removing water blockage after hydraulic fracturing. This work studied the impact of shut-in and IFT reduction on water blockage and found that shut-in can decrease permeability due to water refill, while reducing IFT is beneficial for regained permeability ratio. However, emulsification should be avoided. The study also found that the residual water saturation is larger in micropores and mesopores, indicating that core damage mainly comes from these smaller pores.
Article
Energy & Fuels
Weiyu Tang, Zesen Peng, James J. Sheng
Summary: This study examines the application potential of CO2-based enhanced oil recovery (EOR) methods in shale reservoirs and proposes a method for carbon storage. By conducting fluid simulation and numerical simulation, it is proven that the huff-n-puff (HNP) method can significantly increase CO2 recovery, and the economic analysis takes into account the impact of oil prices and carbon taxes on development scenarios.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Review
Energy & Fuels
Xiaoyu Hou, James J. Sheng
Summary: With the development of the oil industry, improving oil recovery (IOR) technology is becoming more and more important, and nanoemulsions have attracted a lot of attention. However, the properties and characteristics of nanoemulsions are confusing, and the IOR mechanisms of nanoemulsions have not been systematically reviewed. This comprehensive review aims to clarify these problems and provide insights and directions for the further development of nanoemulsions in the oil and gas industries.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Zijian Wei, James J. Sheng
Summary: Thermal cracking in rocks can significantly increase permeability, which is crucial for enhancing oil recovery in ultra-low permeability reservoirs. In-situ thermal stimulation and real-time measurement were performed to evaluate the potential for thermally-induced permeability enhancement in tight sandstone and shale cores. The results showed that thermal cracks rapidly initiated and formed a multi-scale fracture network, leading to permeability improvement up to 11.23 and 29.82 times, respectively.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Wei-Yu Tang, James J. Sheng, Ting-Xue Jiang
Summary: CO2 huff-n-puff is a potential enhanced oil recovery method for tight reservoirs. The spatial distribution of oil saturation was analyzed using NMR method to understand the HNP mechanisms. The results show that soaking improves oil production and increased injection pressure gradient enhances oil recovery in the deep part of the reservoir.
Article
Energy & Fuels
Yingna Du, Chen Huang, Wei Jiang, Qiangwei Yan, Yongfei Li, Gang Chen
Summary: In this study, anionic surfactants modified hydrotalcite was used as a flow improver for crude oil under low-temperature conditions. The modified hydrotalcite showed a significant viscosity reduction effect on crude oil. The mechanism of the modified hydrotalcite on viscosity and pour point of crude oil was explored through characterization and analysis of the modified hydrotalcite and oil samples.
Article
Energy & Fuels
Mohammad Saeid Rostami, Mohammad Mehdi Khodaei
Summary: In this study, a hybrid structure, MIL-53(Al)@MWCNT, was synthesized by combining MIL-53(Al) particles and -COOH functionalized multi-walled carbon nanotube (MWCNT). The hybrid structure was then embedded in a polyethersulfone (PES) polymer matrix to prepare a mixed matrix membrane (MMM) for CO2/CH4 and CO2/N2 separation. The addition of MWCNTs prevented MIL-53(Al) aggregation, improved membrane mechanical properties, and enhanced gas separation efficiency.
Article
Energy & Fuels
Yunlong Li, Desheng Huang, Xiaomeng Dong, Daoyong Yang
Summary: This study develops theoretical and experimental techniques to determine the phase behavior and physical properties of DME/flue gas/water/heavy oil systems. Eight constant composition expansion (CCE) tests are conducted to obtain new experimental data. A thermodynamic model is used to accurately predict saturation pressure and swelling factors, as well as the phase boundaries of N2/heavy oil systems and DME/CO2/heavy oil systems, with high accuracy.
Article
Energy & Fuels
Morteza Afkhamipour, Ebad Seifi, Arash Esmaeili, Mohammad Shamsi, Tohid N. Borhani
Summary: Non-conventional amines are being researched worldwide to overcome the limitations of traditional amines like MEA and MDEA. Adequate process and thermodynamic models are crucial for understanding the applicability and performance of these amines in CO2 absorption, but studies on process modeling for these amines are limited. This study used rate-based modeling and Deshmukh-Mather method to model CO2 absorption by DETA solution in a packed column, validated the model with experimental data, and conducted a sensitivity analysis of mass transfer correlations. The study also compared the CO2 absorption efficiency of DETA solution with an ionic solvent [bmim]-[PF6] and highlighted the importance of finding optimum operational parameters for maximum absorption efficiency.
Article
Energy & Fuels
Arastoo Abdi, Mohamad Awarke, M. Reza Malayeri, Masoud Riazi
Summary: The utilization of smart water in EOR operations has gained attention, but more research is needed to understand the complex mechanisms involved. This study investigated the interfacial tension between smart water and crude oil, considering factors such as salt, pH, asphaltene type, and aged smart water. The results revealed that the hydration of ions in smart water plays a key role in its efficacy, with acidic and basic asphaltene acting as intrinsic surfactants. The pH also influenced the interfacial tension, and the aged smart water's interaction with crude oil depended on asphaltene type, salt, and salinity.
Article
Energy & Fuels
Dongao Zhu, Kun Zhu, Lixian Xu, Haiyan Huang, Jing He, Wenshuai Zhu, Huaming Li, Wei Jiang
Summary: In this study, cobalt-based metal-organic frameworks (Co-based MOFs) were used as supports and co-catalysts to confine the NHPI catalyst, solving the leaching issue. The NHPI@Co-MOF with carboxyl groups exhibited stronger acidity and facilitated the generation of active oxygen radicals O2•, resulting in enhanced catalytic activity. This research provides valuable insights into the selection of suitable organic linkers and broadens the research horizon of MOF hybrids in efficient oxidative desulfurization (ODS) applications.
Article
Energy & Fuels
Edwin G. Hoyos, Gloria Amo-Duodu, U. Gulsum Kiral, Laura Vargas-Estrada, Raquel Lebrero, Rail Munoz
Summary: This study investigated the impact of carbon-coated zero-valent nanoparticle concentration on photosynthetic biogas upgrading. The addition of nanoparticles significantly increased microalgae productivity and enhanced nitrogen and phosphorus assimilation. The presence of nanoparticles also improved the quality of biomethane produced.
Article
Energy & Fuels
Yao Xiao, Asma Leghari, Linfeng Liu, Fangchao Yu, Ming Gao, Lu Ding, Yu Yang, Xueli Chen, Xiaoyu Yan, Fuchen Wang
Summary: Iron is added as a flocculant in wastewater treatment and the hydrothermal carbonization (HTC) of sludge produces wastewater containing Fe. This study investigates the effect of aqueous phase (AP) recycling on hydrochar properties, iron evolution and environmental assessment during HTC of sludge. The results show that AP recycling process improves the dewatering performance of hydrochar and facilitates the recovery of Fe from the liquid phase.
Article
Energy & Fuels
He Liang, Tao Wang, Zhenmin Luo, Jianliang Yu, Weizhai Yi, Fangming Cheng, Jingyu Zhao, Xingqing Yan, Jun Deng, Jihao Shi
Summary: This study investigated the influence of inhibitors (carbon dioxide, nitrogen, and heptafluoropropane) on the lower flammability limit of hydrogen and determined the critical inhibitory concentration needed for complete suppression. The impact of inhibitors on explosive characteristics was evaluated, and the inhibitory mechanism was analyzed with chemical kinetics. The results showed that with the increase of inhibitor quantity, the lower flammability limit of hydrogen also increased. The research findings can contribute to the safe utilization of hydrogen energy.
Article
Energy & Fuels
Zonghui Liu, Zhongze Zhang, Yali Zhou, Ziling Wang, Mingyang Du, Zhe Wen, Bing Yan, Qingxiang Ma, Na Liu, Bing Xue
Summary: In this study, high-performance solid catalysts based on phosphotungstic acid (HPW) supported on Zr-SBA-15 were synthesized and evaluated for the one-pot conversion of furfural (FUR) to γ-valerolactone (GVL). The catalysts were characterized using various techniques, and the ratio of HPW and Zr was found to significantly affect the selectivity of GVL. The HPW/Zr-SBA-15 (2-4-15) catalyst exhibited the highest GVL yield (83%) under optimized reaction conditions, and it was determined that a balance between Bronsted acid sites (BAS) and Lewis acid sites (LAS) was crucial for achieving higher catalytic performance. The reaction parameters and catalyst stability were also investigated.
Article
Energy & Fuels
Michael Stoehr, Stephan Ruoff, Bastian Rauch, Wolfgang Meier, Patrick Le Clercq
Summary: As part of the global energy transition, an experimental study was conducted to understand the effects of different fuel properties on droplet vaporization for various conventional and alternative fuels. The study utilized a flow channel to measure the evolution of droplet diameters over time and distance. The results revealed the temperature-dependent effects of physical properties, such as boiling point, liquid density, and enthalpy of vaporization, and showed the complex interactions of preferential vaporization and temperature-dependent influences of physical properties for multi-component fuels.
Article
Energy & Fuels
Yuan Zhuang, Ruikang Wu, Xinyan Wang, Rui Zhai, Changyong Gao
Summary: Through experimental validation and optimization of the chemical kinetic model, it was found that methanol can accelerate the oxidation reaction of ammonia, and methanol can be rapidly oxidized at high concentration. HO2 was found to generate a significant amount of OH radicals, facilitating the oxidation of methanol and ammonia. Rating: 7.5/10.
Article
Energy & Fuels
Radwan M. EL-Zohairy, Ahmed S. Attia, A. S. Huzayyin, Ahmed I. EL-Seesy
Summary: This paper presents a lab-scale experimental study on the impact of diethyl ether (DEE) as an additive to waste cooking oil biodiesel with Jet A-1 on combustion and emission features of a swirl-stabilized premixed flame. The addition of DEE to biodiesel significantly affects the flame temperature distribution and emissions. The W20D20 blend of DEE, biodiesel, and Jet A-1 shows similar flame temperature distribution to Jet A-1 and significantly reduces UHC, CO, and NOx emissions compared to Jet A-1.
Article
Energy & Fuels
Jiang Bian, Ziyuan Zhao, Yang Liu, Ran Cheng, Xuerui Zang, Xuewen Cao
Summary: This study presents a novel method for ammonia separation using supersonic flow and develops a mathematical model to investigate the condensation phenomenon. The results demonstrate that the L-P nucleation model accurately characterizes the nucleation process of ammonia at low temperatures. Numerical simulations also show that increasing pressure and concentration can enhance ammonia condensation efficiency.
Article
Energy & Fuels
Shiyuan Pan, Xiaodan Shi, Beibei Dong, Jan Skvaril, Haoran Zhang, Yongtu Liang, Hailong Li
Summary: Integrating CO2 capture with biomass-fired combined heat and power (bio-CHP) plants is a promising method for achieving negative emissions. This study develops a reliable data-driven model based on the Transformer architecture to predict the flowrate and CO2 concentration of flue gas in real time. The model validation shows high prediction accuracy, and the potential impact of meteorological parameters on model accuracy is assessed. The results demonstrate that the Transformer model outperforms other models and using near-infrared spectral data as input features improves the prediction accuracy.