Article
Energy & Fuels
Mahmoud Samir El-Yamani, Khalid Al-Ramadan, Dave Cantrell
Summary: The study focuses on the sedimentary, diagenetic, and stratigraphic impact on reservoir quality and porosity evolution of the Middle Jurassic Tuwaiq Mountain Formation in Saudi Arabia. It reveals that dolomite dissolution and calcitization occur locally and are stratigraphically controlled within the formation.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Leilei Yang, Guangyou Zhu, Xinwei Li, Keyu Liu, Linjiao Yu, Zhiye Gao
Summary: This study revealed the influence of lithological minerals and crystal lattice characteristics on dolomitization through experiments and numerical simulations, demonstrating the significant roles of dolomite crystal nucleus and lattice defects in dolomite formation.
Article
Geosciences, Multidisciplinary
Jue Hou, Lun Zhao, Wenqi Zhao, Zhao Feng, Xueke Wang, Xing Zeng
Summary: This study classified and evaluated the pore-throat structures of Carboniferous carbonate reservoirs in the North Truwa oilfield of the Pre-Caspian Basin, and established the classification and evaluation standards of pore-throat structures in different petrophysical facies. The relationship between different petrophysical facies and productions was revealed by combining with the flow profile measured by production logging tools. The results of this study can provide suggestions for the adjustment strategy of water-driven production, laying an important foundation for the fine development of carbonate reservoirs.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geochemistry & Geophysics
Jack G. Murphy, Anne-Sofie C. Ahm, Peter K. Swart, John A. Higgins
Summary: The records of lithium isotopic composition in seawater preserved in shallow-marine carbonate sediments are valuable for studying the links between silicate weathering, clay formation, global carbon cycle, and Earth's climate over geological time. This study presents measurements of lithium isotopic composition in Neogene shallow-marine carbonates and demonstrates the effects of mineralogy and diagenetic alteration on the variability of bulk sediment δ Li-7 values. The findings suggest that robust 'snapshots' of seawater δ Li-7 values in the past can be obtained from shallow-water marine carbonate sediments.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Energy & Fuels
Zhou Jingao, Yu Zhou, Wu Dongxu, Ren Junfeng, Zhang Daofeng, Wang Shaoyi, Yin Chen, Liu Yuxin
Summary: By studying two types of dolomite reservoirs in the Ordos Basin, we found that different diagenetic processes and fillings led to changes in reservoir porosity, which is of great significance for the restoration of porosity evolution in other basins or series of strata.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2022)
Article
Geosciences, Multidisciplinary
Yangrui Guo, Wenfeng Deng, Xi Liu, Kai Kong, Wen Yan, Gangjian Wei
Summary: This study focuses on the Delta(47) values of island carbonates from the Meiji Reef in the South China Sea to constrain the diagenetic environment, finding that most diagenetic alteration likely occurred at water depths around 200 meters below sea level at temperatures between 15 and 28 degrees Celsius. The fluids involved in the formation of diagenetic calcites and dolomites have similar delta O-18 values to modern seawater.
Article
Energy & Fuels
Yousef Ibrahem, V. P. Morozov, V Sudakov
Summary: This study focused on the sedimentary rocks of the Lower Cretaceous in the Euphrates Graben area, using various techniques like core description, thin section observations, and electron microscopy. The research identified different types of dolomites in the Judea Formation, indicating a two-stage diagenetic history for the sediments, which led to improved reservoir properties by enhancing porosity.
Article
Geosciences, Multidisciplinary
Aura Samid Garcia, Lyubov Afanasievna Krasnoshchekova, Irfan Shaaban Asaad, Vladimir Borisovich Belozerov, Ali Ismail Al-Juboury
Summary: Paleozoic rocks in Western Siberia may have significant hydrocarbon resources, but effective exploration methods are unclear. This study provides new insights into reservoir formation by analyzing the Paleozoic succession of the North-Ostaninsk field. Dolomitization has affected the carbonate rocks, and four generations of dolomite have been identified. The last generation coincides with the presence of a reservoir and is derived from downward infiltration of meteoric water. This new understanding can help predict similar hydrocarbon accumulations in unexplored areas.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Vahid Tavakoli
Summary: Understanding the relationship between dolomitization and permeability changes is crucial in carbonate reservoirs. This study in the central Persian Gulf shows that dolomitization increases permeability by improving pore connectivity through various diagenetic processes. Different crystal shapes of dolomite also affect permeability variations in the samples.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Energy & Fuels
Ye Yu, Li Fengfeng, Song Xinmin, Guo Rui
Summary: The study focused on the transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis in the Cretaceous strata of the Mesopotamia Basin, Middle East. Three ways of biological transformation of rocks were identified, mainly occurring during the penecontemporaneous phase. This process was influenced by factors such as rock type, sea level decline, burrow abundance, infillings, and water environment. The physical properties of muddy carbonate rocks were improved by bioturbation, especially when burrows were filled with coarse-grained debris or fine-crystalline dolomite.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2021)
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
Energy & Fuels
Bo Jiu, Wenhui Huang, Nana Mu, Yuan Li
Summary: Continuous advancements in oil and gas exploration technology have shifted the focus towards ultradeep reservoirs due to increasing demand for resources. This study examines the carbonate karst reservoirs in the Ordovician Ma5 Member in the southeastern Ordos Basin, analyzing development characteristics, types, and influencing factors of paleokarst reservoirs. Petrology and geochemistry indicate three types of karstification processes, controlled by freshwater and thermochemical sulfate reduction, resulting in diverse dissolution pores and fractures in the reservoirs.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Energy & Fuels
Xuemei Zhang, Qing Li, Xuelian You, Lichi Ma, Anyu Jing, Wen Tian, Lang Wen
Summary: This study investigates the Lower Paleozoic carbonate strata in the Dongying Depression, identifying the characteristics of dolomite, reservoir spaces, and porosity evolution. Different types of dolomite are formed by various origins, such as seawater and hydrothermal fluids, contributing to reservoir heterogeneity. Dissolution plays a key role in forming high-quality dolomite reservoirs, with fractures and hydrothermal fluids being significant factors in the study area.
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
Ma Baoquan, Chen Shumin, Yan Weilin, Lin Chengyan, Zhang Hong, Sun Zhifeng, Zheng Jiandong, Wang Ya, Wu Shangxin, Wang Jingyan
Summary: This study analyzed the influence of sedimentary diagenesis on the pore structure and physical properties of low permeability sandstone reservoirs, and classified the pore structures in the study area into four types to predict favorable reservoir areas. Areas with type I and type II pore structures were found to have high reservoir quality, with porosity between 10% and 25% and permeability between 1 mD and 50 mD, suggesting them as regions for optimized exploration and development.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
