Article
Energy & Fuels
Fuyong Wang, Fanchao Zeng, Lu Wang, Xianmu Hou, Hui Cheng, Jian Gao
Summary: This study analyzed the fractal characteristics of pore spaces in tight sandstones from the Ordos Basin in China, using NMR and RCP techniques. It showed that the fractal dimensions of pore spaces with movable fluids were negatively correlated with permeability and reservoir quality index, with fractal dimensions approaching 3 indicating less favorable petrophysical properties. Different fractal models were compared for calculating fractal dimensions, with the 3D capillary model found to be the most accurate for evaluating tight sandstone properties.
Article
Geosciences, Multidisciplinary
Yifan Zhang, Kelai Xi, Yingchang Cao, Xianzhang Yang, Zhenping Xu, Lu Zhou, Guoding Yu, Zhanghua Han, Zehan Zhang
Summary: Understanding diagenetic fluid types and their effects on diagenesis is crucial for identifying control factors of reservoir characteristics and predicting reservoir sweet spots. This study investigated strong cementation in Lower Jurassic Ahe Formation sandstones near a deep-rooted fault using petrographic and geochemical methods. The results suggest the involvement of deep fluids in reservoir diagenesis and highlight the negative effects of deep fluids on diagenetic processes.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Wenjun Xu, Jinzhou Zhao, Jianguo Xu
Summary: This paper introduces a new Fracability Index (FI) model, which evaluates the potential candidate layers for hydraulic fracturing in unconventional reservoirs by considering the possibilities of complex hydraulic fracture network and large stimulation reservoir volume. The model takes into account essential factors like brittleness, fracture toughness, natural fractures, and in situ stresses, providing a useful tool for selecting the most suitable candidates for fracturing treatments.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Qing Guo, Mancang Dong, Hengbo Mao, Jiangtao Ju
Summary: Quantitatively characterizing the micro-scale heterogeneity of pore throats is essential in accurately describing the influence of pore structures on fluid occurrence characteristics in tight sandstone reservoirs. This study systematically investigated the pore throat heterogeneity of a specific reservoir and its impact on fluid occurrence state using various testing methods. The research found that intergranular pores and feldspar dissolution pores were the main pore types in the target layer. The study also revealed that the uniformity of throat development and pore radius played significant roles in determining the reservoir permeability. Additionally, different pore types exhibited distinct movable fluid saturations.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Wenchao Dou, Mian Lin, Luofu Liu, Langbo Jia
Summary: This study investigated the relationship between chlorite rims and porosity evolution in the Chang 7 sandstones of the Upper Triassic Yanchang Formation in the Ordos Basin in northcentral China. The results showed that chlorite rims inhibited the formation of quartz cementation, but other factors such as compaction and other cements also controlled the porosity evolution of sandstones. Chlorite rims only played an important role in porosity preservation when quartz cementation was the main process of porosity destruction.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Maryam A. Abdulkarim, Adrian R. Muxworthy, Alastair Fraser
Summary: This paper describes a magnetic method for determining the position and thickness of the oil-water transition zone (OWTZ) in hydrocarbon reservoirs. The study found distinct signatures around the oil-water interface, which were attributed to the increasing concentration of hexagonal pyrrhotite and/or lepidocrocite. These observations are important for understanding biodegradation and hydrolysis in hydrocarbon reservoirs.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yogarajah Elakneswaran, Amir Ubaidah, Miku Takeya, Mai Shimokawara, Hirofumi Okano
Summary: This study evaluated the influence of interface properties of sandstone/brine and thermodynamic equilibrium of sandstone minerals on wettability alteration during low-salinity water flooding. By using a triple-layer surface complexation model and experimental data verification, it was found that consideration of thermodynamic equilibrium significantly increased the surface potential, resulting in a stronger repulsive force and a more water-wet condition.
Article
Geosciences, Multidisciplinary
Sebastian Niegel, Matthias Franz
Summary: The Mesozoic succession in the North German Basin contains permeable sandstones that are used for geothermal heat production. The sandstones have high permeability due to undercompacted grain fabrics, low abundance of authigenic minerals, and large secondary porosity volumes. Petrographic methods were used to study the diagenesis of sandstones, and four diagenetic pathways were identified. The knowledge of these pathways will help improve predictions of Mesozoic hydrothermal reservoirs.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Energy & Fuels
Oualid M' Barki, Sean Brame, Orlando Castellanos Diaz, Amit Katiyar, Matt Crosley, Troy Knight, Quoc P. Nguyen
Summary: The study found that the clay content of the rock has a critical impact on the efficiency of the foaming surfactant at high temperature, and there is a strong correlation between permeability, aspect ratio and foam apparent viscosity at steady-state. Therefore, the mineralogy and microstructure of natural sandstone reservoirs play a crucial role in the successful design of a steam foam process.
Article
Geosciences, Multidisciplinary
Peng Yang, Keyu Liu, Jianliang Liu, Shuang Yu, Biao Yu, Maoguo Hou, Luya Wu
Summary: The study reveals that there were two oil charge events in the Shunbei Oilfield, with the first occurring in the latest Silurian around 426 Ma, characterized by relatively low maturity oil, and the second occurring during the early Carboniferous around 330 Ma, characterized by relatively high maturity oil. This research emphasizes the importance of stable tectonic setting and excellent sealing capability of cap rocks for reservoir preservation, providing new insights for future exploration.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Energy & Fuels
Guangli Fan, Meng Li, Xinxiao Chen, Aleksandra Palyanitsina, Anton Timoshin
Summary: This study investigated the implementation of Nanosilica particles in chemical flooding processes for the petroleum industry, showcasing their enhancement of polymer performance and oil recovery. Experimental results suggest that the Nanosilica-polymer system is most effective in improving oil recovery.
Article
Chemistry, Physical
Aref Nafisifar, Abbas Khaksar Manshad, Seyed Reza Shadizadeh
Summary: A new anionic surfactant synthesized from natural base material linseeds demonstrated high efficiency in chemical enhanced oil recovery, with characterization conducted using FTIR, HNMR, and TGA to ensure accuracy and thermal stability, achieving significant improvement in main oil recovery mechanisms.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Mahdi Shayan Nasr, Ehsan Esmaeilnezhad, Ahmad Allahbakhsh, Hyoung Jin Choi
Summary: Nanofluids based on nitrogen-doped graphene quantum dots show potential applications in enhanced oil recovery by improving wettability and reducing oil/water interfacial tension in carbonate rocks and sandstones, resulting in increased oil recovery factors.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Geochemistry & Geophysics
Xiong Liu, Desheng Zhou, Le Yan, Shun Liu, Yafei Liu
Summary: A model suitable for evaluating a tight sandstone reservoir is established, considering the influence of capillary force, osmotic pressure, production pressure difference, and starting pressure gradient on oil-water replacement rate. Results show that higher relative permeability of water phase, lower relative permeability of oil phase, smaller oil-water viscosity ratio lead to higher oil-water replacement rate.
Article
Geochemistry & Geophysics
Guanyu Zhang, Qiang Fu, Guangrong Peng, Xudong Wang, Lili Zhang, Xuhong Xiang, Zhiwei Zhu
Summary: This study explores the geological and diagenetic factors affecting Paleogene sandstone reservoirs in the Baiyun Sag region, crucial for oil and gas exploration. Through advanced methodologies, it analyzes the petrological characteristics, pore structures, physical properties, and key diagenetic processes of the Paleogene Zhuhai and Enping formations. The findings provide invaluable insights into the diagenetic evolution of sandstone reservoirs in the Baiyun Sag and have significant implications for guiding future oil and gas exploration efforts in the region.