Insight into the Pore Structures and Its Impacts on Movable Fluid in Tight Sandstones

Ren, Dazhong; Yang, Fangxing; Li, Rongxi; Zhou, Desheng; Liu, Dengke; Li, Ying

doi:10.1155/2020/8820023

Cited by 4 publications

(4 citation statements)

References 29 publications

(31 reference statements)

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“…Intercrystalline pores refer to pores developed inside authigenic minerals. The larger the volume of kaolinite crystals, the better the development of intercrystalline pores (Schmitt et al, 2015;Ren et al, 2020;Zhao et al, 2020). This is due to the fact that kaolinite crystals are stacked together in a book-like form and are not sensitive to water.…”

Section: Pore Typesmentioning

confidence: 99%

Experimental evaluation of microscopic pore structure and fluid migration characteristics of coal-measure sandstone reservoirs

Pan

Peng

2022

Front. Earth Sci.

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Research on the microscopic migration characteristics of fluids in coal measure sandstone has always been a hot spot in the evaluation of reservoir properties. In this study, taking the Yan’an Formation sandstone reservoirs in the Block A of the Ordos Basin as an example, the pore structures and fluid migration characteristics of coal-measure sandstones are systematically studied using a large number of thin sections, SEM (Scanning Electron Microscope), NMR (Nuclear Magnetic Resonance), relative permeability and water-flooding test results. The results show that the Jurassic sandstones in the target layer mainly develop lithic quartz sandstone, and the main pore types are intergranular and dissolution pores, followed by a small amount of intercrystalline pores. The surface porosity of the target sandstones mainly ranges from 7.90 to 10.79%, with an average value of 8.78%. The good correlation between porosity and permeability indicates that the target layer is a pore-type reservoir. The T2 relaxation time of the target layer is mainly distributed within 100 ms. Moreover, the reservoir of the Yan’an Formation has a high saturation of movable fluids, which is mainly distributed in 43.17–71.24%, with an average value of 56.90%. Meanwhile, samples with fractures have higher movable fluid saturations. In addition, the average irreducible water saturation of the Yan’an Formation sandstone reservoir is 35.14%, and the final oil displacement efficiency is 51.14% on average. There is a good positive correlation between the oil displacement efficiency and the co-permeability zone. As the co-permeability zone range increased from 15 to 55%, the oil displacement efficiency increased from 30 to 65%. When the cores develop fractures, they have characteristics of high permeability, high oil recovery rate, high oil displacement efficiency in the anhydrous period, low irreducible water saturation and low residual oil saturation.

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Section: Pore Typesmentioning

confidence: 99%

Experimental evaluation of microscopic pore structure and fluid migration characteristics of coal-measure sandstone reservoirs

Pan

Peng

2022

Front. Earth Sci.

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“…Аспек- ADVANCES IN CURRENT NATURAL SCIENCES № 10, 2021   EARTH SCIENCES (25.00.00)  ты влияния литологических параметров на фильтрационно-емкостные и петрофизические свойства пород рассмотрены в работах таких исследователей, как R. Weibel [3], K. Bjørlykke [4], L. Liu [5] и др. Установлено, что сложная поровая структура является решающим фактором, оказывающим воздействие на особенности фильтрации флюида в пластах-коллекторах, и создает определенные сложности при разведке и разработке месторождений [6]. Однако подробное изучение строения порового пространства продуктивных песчаников с акцентом на литологию открывает возможности для построения максимально точных геологических моделей многопластовых залежей углеводородов.…”

Section: Abstract: Krasnoyarsk Territory Sandstones Vankor Permeability Terrigenous Reservoir Porosityunclassified

Lithological Features Influence on Porosity and Permeability of Oil-Bearing Sandstones

Cherdantseva¹,

Kravchenko²,

Krasnoschekova³

2021

УСЕ (ACNR)

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“…Reservoir quality increases with the degree of complexity of microscopic pore structures, and multiple approaches have been used to characterize the continuous distribution of pore networks in heterogeneous dolostones 14 . The characteristics of both the pore structure and movable fluid are significant properties for controlling the flow regularity in pores in tight reservoirs 15 . Low‐velocity non‐Darcy flows exist in shale and tight reservoirs because of rock–liquid interactions 16 .…”

Section: Introductionmentioning

confidence: 99%

“…14 The characteristics of both the pore structure and movable fluid are significant properties for controlling the flow regularity in pores in tight reservoirs. 15 Low-velocity non-Darcy flows exist in shale and tight reservoirs because of rock-liquid interactions. 16 Further, because of narrow pore throats, water flooding in unconventional oil reservoirs is extremely challenging and becomes almost impossible at high injection pressures and low injection rates.…”

Section: Introductionmentioning

confidence: 99%

Pore structure and fluid mobility of tight carbonate reservoirs in the Western Qaidam Basin, China

Chen

Zheng

Guo

et al. 2023

Energy Science & Engineering

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Tight carbonate reservoirs in the Western Qaidam Basin have complex lithologies and pore structures. The oil–water mobility law in reservoirs has not yet been completely determined, restricting the formulation of rational reservoir development methods. To bridge this gap, in this study, we used several test methods, such as casting thin sections, mercury intrusion, and nuclear magnetic resonance, to obtain the pore structure and oil–water displacement characteristics of tight carbonate reservoirs in the Western Qaidam Basin. The pore structures of the reservoirs could be categorized into three types: microfractures + dissolved pores + micropores (MFD), microfractures + micropores (MF), and matrix (M). The characteristics of single‐phase oil seepage and water flooding in reservoirs with various pore structures differed evidently. For the MF‐ and M‐types, the water‐locking effect caused by the strong capillary force affected oil charging in the micropores. The effect of the pressure drop on the MFD‐type algal limestone was less than that on the MF‐type limestone (dolomite) because of the occurrence of a non‐Darcy flow. The MFD‐type, which contained microfractures, had preferential seepage channels, resulting in obvious fluid channeling and low water displacement efficiency. Oil−water displacement mainly occurred in the dissolved pores and microfractures, suggesting that starting oil accumulation in the micropores was crucial. This study will assist in efficient development of tight carbonate reservoirs in the Western Qaidam Basin.

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Insight into the Pore Structures and Its Impacts on Movable Fluid in Tight Sandstones

Cited by 4 publications

References 29 publications

Experimental evaluation of microscopic pore structure and fluid migration characteristics of coal-measure sandstone reservoirs

Experimental evaluation of microscopic pore structure and fluid migration characteristics of coal-measure sandstone reservoirs

Lithological Features Influence on Porosity and Permeability of Oil-Bearing Sandstones

Pore structure and fluid mobility of tight carbonate reservoirs in the Western Qaidam Basin, China

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