Review
Energy & Fuels
Jingxuan Xu, Wensheng Lin, Xi Chen, Hua Zhang
Summary: This review summarizes and analyzes the characteristics and differences of several typical unconventional natural gas liquefaction processes compared to traditional natural gas liquefaction processes, and presents a state-of-the-art review of the recent progress on design and optimization of unconventional natural gas liquefaction processes.
FRONTIERS IN ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Li Jia, Shoujian Peng, Jiang Xu, Fazhi Yan
Summary: This study investigated the mechanism of fluid migration and interlayer interference in multilayer superimposed gas-bearing systems through coproduction experiments. It found a coupling effect between reservoir pressure gradient, matrix shrinkage, and effective stress, affecting reservoir pressure evolution. Interlayer interference increases gradually as the difference in pressure gradients between reservoirs increases.
Article
Energy & Fuels
Qifeng Jia, Dameng Liu, Xiaoming Ni, Yidong Cai, Yuejian Lu, Zongyuan Li, Yingfang Zhou
Summary: This study investigates the mechanism of inter-well interference and the changes in productivity after infilling coalbed methane wells. The results show that inter-well interference enhances the dynamics of methane desorption and gas migration, leading to improved efficiency in coalbed methane production.
Article
Energy & Fuels
Boris V. Malozyomov, Vladimir Ivanovich Golik, Vladimir Brigida, Vladislav V. Kukartsev, Yadviga A. Tynchenko, Andrey A. Boyko, Sergey V. Tynchenko
Summary: Decarbonization of the mining industry through energy generation closure, coal mine methane cogeneration, and internal consumption is crucial for sustainable development. However, deep underground mining faces challenges in utilizing man-made gas reservoirs. This study aims to improve drilling parameters for increasing methane production from unconventional coal-gas collectors. The innovative approach involves using established patterns of better natural stability of boreholes and optimizing them as spatial orientation parameters.
Review
Energy & Fuels
Temoor Muther, Haris Ahmed Qureshi, Fahad Iqbal Syed, Hassan Aziz, Amaar Siyal, Amirmasoud Kalantari Dahaghi, Shahin Negahban
Summary: This article discusses the classification, technology, and exploitation methods of unconventional hydrocarbons, emphasizing the importance of global unconventional hydrocarbon resources, as well as the geological and petrophysical characteristics of different types of unconventional hydrocarbon resources.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Thermodynamics
Chenghong Wang, Daming Sun, Qie Shen, Keyi Shen, Jianshe Linghu, Xiaodong Wang
Summary: Four typical nitrogen reverse Brayton cycles (N-2-RBCs) were studied to reveal the efficiency difference in recovering coalbed methane (CBM). The N-2-RBC with parallel arrangement of expanders showed better matching between hot and cold composite curves. The liquefaction process using parallel N2-RBC achieved the lowest specific power consumption (SPC) of 0.72 kWh center dot kg(-1) and the highest figure of merit of 31.11%, with the lowest exergy loss of 180.1 kW and a total investment of 4047.76 k$ for a liquefaction capacity of 10 tons per day.
Article
Energy & Fuels
Cheng Leli, Zhao Shaoze, Yin Senlin, Chen Gongyang, Chen Ling, Xiong Ting
Summary: This study analyzed the development of multi-layer gas reservoirs and its impact on production efficiency. Through coupled calculations, the dynamic gas production was predicted, showing that the investment cost of single well multi-layer production is lower, and the stable production time is longer.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Environmental Sciences
Kimberley A. Taylor, David Risk, James P. Williams, Grant D. Wach, Owen A. Sherwood
Summary: This study investigated the presence of methane in groundwater in the Stellarton Basin, Nova Scotia, Canada, finding that the majority of methane is of microbial origin, with some trace thermogenic gas likely originating from coal mines in the area. The data obtained in this study may be used as baseline information for future coal-bed methane operations in the region.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Ruijing Zhu, Rongxi Li, Xiaoli Wu, Xiaoli Qin, Bangsheng Zhao, Futian Liu, Di Zhao
Summary: This study investigated the fluid inclusions in the Permian sandstone and Ordovician dolomite reservoirs in the central-southern Ordos Basin, finding two phases of fluid inclusions that recorded the history of natural gas formation and accumulation. The diagenetic fluids in these reservoirs showed medium-low temperature and moderate-low salinity, with natural gas accumulation being related to the Yanshanian tectonic movement.
Article
Energy & Fuels
Lin Jiang, Yan Song, Wen Zhao, Dongmei Bo, Shaobo Liu, Jiaqing Hao
Summary: This study aims to elucidate the CBM enrichment mechanism in the southern Qinshui Basin, China, and provides new insights into CBM enrichment patterns. The findings reveal a high-yield model of CBM accumulation and the primary challenges for CBM development in China. This study represents a valuable contribution toward unlocking China's CBM potential through improved geological characterization.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Zhijun Zhang, Boyang Wang, Yunfei Cui
Summary: In this study, a desorption model was established based on coal samples to analyze the CBM desorption mechanisms and production characteristics. The results showed a significant relationship between desorption time and cumulative desorption quantity, and the desorption process was divided into four stages.
Article
Chemistry, Multidisciplinary
Zhijun Zhang, Boyang Wang, Yunfei Cui
Summary: This study established a mathematical model to accurately describe the relationship between CBM desorption characteristics and well productivity based on CBM natural desorption experimental data. The CBM natural desorption process was divided into four stages, which corresponded to different stages of CBM well production. In addition, the study found that CBM adsorption time was closely related to factors such as CBM desorption rate, gas content, and vitrinite/inertinite ratio.
Article
Energy & Fuels
Shuji Tamamura, Takuma Murakami, Akio Ueno, Satoshi Tamazawa, Tamotsu Kiyama, Hidenori Inomata, Hiroyuki Matsumoto, Kagemi Uchida, Yoshiaki Suzuki, Jun Aizawa, Katsuhiko Kaneko
Summary: Isotopic analysis of rocks and sedimentary rocks from the Kushiro Coal Mine in Japan reveals the presence of thermogenic methane in some closed pores.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Article
Energy & Fuels
Shuya Chen, Kunzhi Xie, Yanping Shi, Zishuo Li, Xianyu Yang, Jihua Cai
Summary: The low permeability of coalbed methane (CBM) reservoirs is attributed to cementing minerals, which block the flow of water and gas in the pores and fractures. Acid stimulation is a promising method to improve coal permeability by dissolving these inorganic minerals. Laboratory experiments investigated the interactions between various acids and coal samples, leading to the optimization of a compound acid system that greatly enhanced CBM recovery by increasing coal porosity and permeability.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Geological
Shirong Cao, Zhaolong Ge, Di Zhang, Zhe Zhou, Yiyu Lu, Hanyun Zhao
Summary: This study investigates the rock-breaking mechanism and pore structure evolution of typical reservoir rocks under ultra-high pressure water jet (UHP-WJ) impingement. The results show that different types of rocks exhibit different fracture mechanisms and pore structure evolutions under UHP-WJ impact. These findings provide important theoretical references for optimizing the development of unconventional natural gas reservoirs.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Environmental
Yong Li, Zhuangsen Wang, Shuheng Tang, Derek Elsworth
Summary: Differentiating between adsorbed and free methane in coal and shale is essential for gas recovery strategies and greenhouse gas control. The proposed method using nuclear magnetic resonance spectroscopy successfully determines adsorbed/free methane ratios and compares favorably with standard isothermal adsorption measurements.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Geosciences, Multidisciplinary
Bin Zhang, Yafei Zhang, Suping Zhao, Wei He, Shu Tao, Zhejun Pan, Yi Cui
Summary: This study conducted CH4 isothermal adsorption measurements on 64 coal samples from western Guizhou Province in China and quantitatively analyzed the desorption processes of coalbed methane (CBM). The results indicate that coalification affects the Langmuir volume and pressure, which tend to increase with higher vitrinite reflectance. The CBM desorption process was divided into four stages (inefficient, slow, fast, and sensitive) using three key pressure nodes. The fast and sensitive desorption stages are crucial for achieving high gas production.
FRONTIERS OF EARTH SCIENCE
(2023)
Article
Energy & Fuels
Longde Sun, Wenyuan He, Zihui Feng, Huasen Zeng, Hang Jiang, Zhejun Pan
Summary: This study investigates the hydrocarbon generation mechanism, occurrence of oil and gas, and pore structure characteristics of continental Gulong Shales through a series of pyrolysis experiments. The results reveal that the favorable oil generation window for Gulong shale is between Ro 0.9 and 1.6%, and the shale pore structure and permeability change accordingly with oil generation.
Article
Energy & Fuels
Guanglei Cui, Wangxing Cheng, Wei Xiong, Tianyu Chen, Yong Li, Xia-Ting Feng, Jishan Liu, Derek Elsworth, Zhejun Pan
Summary: The co-production of gas from coalbeds and tight formations is a viable means to improve well productivity. However, previous studies have not paid much attention to the effectiveness of gas co-production with regard to well types. In this study, a coupled model is proposed to analyze the impacts of gas co-production and different reservoir interactions. The results provide recommendations for the use of horizontal or vertical wells based on the characteristics of the reservoirs and well life.
Article
Engineering, Geological
Jun Zhang, Qiangang Yu, Yuwei Li, Zhejun Pan, Bo Liu
Summary: This study investigates the vertical propagation mechanism of hydraulic fractures in interlayered brittle shale formations. Experimental modeling and quantitative analysis are conducted to study the effects of geological and engineering factors on fracture propagation behavior. The results show that interlayer dip angle, vertical in situ stress difference, and interface cementation strength are important factors affecting fracture propagation. The brittleness characteristics of the interlayer also have a significant impact. The findings provide a deeper understanding of fracture geometry and the fracture intersection mechanism, offering accurate guidance for fracturing parameter optimization.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Hongyan Qu, Yan Peng, Zhejun Pan, Xiangdong Xu, Fujian Zhou
Summary: Water-flooding is an effective method for developing extra-low permeability oil reservoirs, but water-rock interactions can alter geomechanical properties and impact the propagation of water-flooding induced fractures (WIFs). This study proposes a method to calculate WIF propagation length and establishes numerical models considering the effect of water-rock interactions. The models are validated and the mechanism and impact of water-rock interactions on WIF propagation are analyzed.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Thermodynamics
Ruirui Li, Luqing Zhang, Jian Zhou, Zhenhua Han, Zhejun Pan, Holger Schuettrumpf
Summary: This study investigates the influence of mineral particle shape and pore-filling natural gas hydrate (NGH) on permeability anisotropy. Simulation methods are used to construct numerical samples and calculate anisotropic permeabilities. The results show that elongated particles have minimal effect on permeability anisotropy, while preferential alignment of plate-shaped particles is the main cause. Understanding the formation mechanism of permeability anisotropy has potential applications in NGH exploitation, groundwater environment protection, and geological disaster prevention.
Article
Energy & Fuels
Yong Li, Lifu Xu, Jianqi Chen, Weiqi Zhang, Derek Elsworth
Summary: The hydration state plays a crucial role in determining the pore structure and mechanical properties of shale, which directly affect the migration and production of geofluids. Through experiments and measurements, we found that hydration leads to a decrease in pore space, deformation modulus, and imbibition rate. Understanding the impact of hydration on shale properties is essential for reservoir surveillance and management.
Review
Geosciences, Multidisciplinary
Changqing Fu, Yi Du, Wenlei Song, Shuxun Sang, Zhejun Pan, Ning Wang
Summary: Automated Mineralogy (AM) is a semi-automatic mineralogical tool that uses a scanning electron micrography-energy dispersion spectrometry (SEM-EDS) platform. It can analyze sedimentary environments, diagenetic evolution processes, and evaluate oil and gas reservoirs. The combination of AM and CT scanning can improve the accuracy of mineral distribution and be applied to study fluid reactive transport effects.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Engineering, Chemical
Duo Wang, Sanbai Li, Dongxiao Zhang, Zhejun Pan
Summary: The transport mechanism of densely-packed proppant bed is numerically investigated using the lattice Boltzmann-discrete element coupling method (LB-DEM). This study focuses on the bedload transport of settled proppants in the primary fracture. The results show a nonlinear relationship between particle flux and fluid flux, which is attributed to the shear-thinning property of the proppant bed. The research contributes to an improved hydraulic fracturing operation by optimizing the fracturing fluid injection scheme and proppant flowback control.
Article
Energy & Fuels
Ziwei Wang, Yong Li, Zhuangsen Wang, Leixin Zhou
Summary: Temperature and pore structure and properties have an effect on adsorption capacity. The adsorption capacity of coal decreases with increasing temperatures, with the maximum volume adsorbed being 11.77-33.34 cm(3)/g at 20°C and 9.87-28.99 cm(3)/g at 100°C. Coals are dominated by 0.3-0.8nm micropores, and the variation in isosteric heat of adsorption is influenced by coal surface roughness and intermolecular forces.
Review
Energy & Fuels
Biao Hu, Yuanping Cheng, Zhejun Pan
Summary: The pore structures in coal are crucial for the occurrence and migration of coalbed methane (CBM), which plays a significant role in CBM extraction, utilization, and coal mining disaster prevention. Existing pore classification methods for coal have their drawbacks, thus this paper systematically reviews previous methods and proposes a new pore classification based on the characteristics of CH4 occurrence and migration in coal. This new method categorizes pore structures into four types and provides a more intuitive understanding of CBM occurrence and migration.
GAS SCIENCE AND ENGINEERING
(2023)
Review
Energy & Fuels
Qing Liu, Mengdi Sun, Xianda Sun, Bo Liu, Mehdi Ostadhassan, Wanxia Huang, Xiaoxia Chen, Zhejun Pan
Summary: X-ray computed tomography (X-ray CT) scanning is a non-destructive visualization technology that can be used to characterize multiscale shale pore structures and assess their permeability. Various imaging techniques, such as micro-CT, nano-CT, FIB-SEM, and contrast agent injections, provide a powerful approach for evaluating shale microstructures. Additionally, digital rock physics (DRP) based on 3D visualization can be used for flow modeling and predicting transport properties. CT scanning can also capture the significant evolution of microstructures during geological processes or hydrocarbon exploitation.
GAS SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Lifu Xu, Yong Li, Xiaoguang Sun, Ziling Li, Shuang Gao, Weiqiang Hu, Yuan Zhang
Summary: This study analyzed shale cores from the Benxi and Taiyuan formations of the Pennsylvanian and the Shanxi Formation of the Cisuralian in the eastern Ordos Basin, and found that the shales are rich in organic matter but have low gas generation potential. The gas content of the shales overall is positively correlated with the total organic carbon content. The gas content of deltaic shale is mainly affected by the organic carbon content, while tidal-lagoonal shale is influenced by various factors.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Energy & Fuels
Longde Sun, Wenyuan He, Zihui Feng, Huasen Zeng, Hang Jiang, Zhejun Pan
Summary: The hydrocarbon generation mechanism, occurrence of oil and gas, and pore structure characteristics of continental shale oil were studied through a series of experiments and scientific analysis. The results show that Gulong shale has favorable conditions for oil generation and gas enrichment. These experimental findings are of great significance for the exploration and discovery of continental shale oil.