Influencing factors of oil-bearing capacity in tight sandstones based on pore structure characterization: a case study of the Fuyu reservoir in the Xinmiao oilfield, Southern Songliao Basin
Abstract
The tight sandstone reservoir exhibits a complex pore structure and strong heterogeneity. Accurate characterization of its pore structure is crucial for improving the efficiency of tight oil development. This study investigates tight sandstone samples exhibiting different oil-bearing levels from the Fuyu oil reservoir of the fourth member of the Quantou Formation in the Xinmiao area, located in the southern Songliao Basin. The influence of pore structure on oil-bearing capacity was investigated through a series of systematic experiments, including low-pressure nitrogen adsorption (LPN2A), high-pressure mercury intrusion (HPMI), constant-rate mercury intrusion (CRMI), nano-computed tomography (nano-CT), and nuclear magnetic resonance (NMR). The results show that: (1) The microscopic pore structure influences the macroscopic oil-bearing capacity. As the oil-bearing level of the sample increases, the corresponding pore structure gradually improves, and the oil saturation increases to 32.93%, 40.36%, 42.61%, and 50.80%, respectively. (2) The oil saturation of fluorescent samples was primarily contributed by small pores (T2 < 10 ms), with a contribution rate of 78.17%. The oil saturation of oil trace and oil flecked samples was mainly contributed by small pores and medium pores (10 < T2 < 100 ms), with combined contribution rates of 93.75% and 84.35%, respectively. The oil saturation of oil immersion samples was primarily contributed by medium pores and large pores (T2 > 100 ms), with a contribution rate of 54.45%. (3) Pore-throat connectivity and its heterogeneity are the key factors influencing the oil-bearing capacity of tight sandstone in the study area. The pore-throat radius, connected pore throat volume percentage and NMR fractal dimension are the best parameters to characterize oil-bearing capacity. (4) The lower limit for oil-bearing capacity in the tight sandstone reservoir of the study area is oil trace, and the corresponding threshold values of a pore–throat radius of 1.19 μm, a connected pore–throat volume percentage of 47.5%, and an NMR fractal dimension of 2.8169. This research establishes a quantitative linkage between pore-throat structure and oil-bearing capacity, providing diagnostic parameters for tight oil evaluation.
Data availability
The data are available from the corresponding author upon reasonable request.
References
Jia, C., Pang, X. & Song, Y. Whole petroleum system and ordered distribution pattern of conventional and unconventional oil and gas reservoirs. Pet. Sci. 20 (1), 1–19. https://doi.org/10.1016/j.petsci.2022.12.012 (2023).
Stolz, J., Ziegler, C. & Griffin, W. Global unconventional oil and gas reserves and their development. In Environmental Impacts from the Development of Unconventional Oil and Gas Reserves (eds Stolz, J. et al.) 3–18 (Cambridge University Press, 2022). https://doi.org/10.1017/9781108774178.003.
Zhou, N. et al. Limits and grading evaluation criteria of tight oil reservoirs in typical continental basins of China. Pet. Explor. Dev. 48 (5), 1089–1100. https://doi.org/10.1016/S1876-3804(21)60093-9 (2021).
Jia, C. Breakthrough and significance of unconventional oil and gas to classical petroleum geology theory. Pet. Explor. Dev. 44 (1), 1–10. https://doi.org/10.1016/S1876-3804(17)30002-2 (2017).
Dong, X., Meng, X. & Pu, R. Impacts of mineralogy and pore throat structure on the movable fluid of tight sandstone gas reservoirs in coal measure strata: A case study of the Shanxi formation along the southeastern margin of the Ordos basin. J. Petrol. Sci. Eng. 220 (A), 111257. https://doi.org/10.1016/j.petrol.2022.111257 (2023).
Meng, Z., Sun, W., Liu, Y., Luo, B. & Zhao, M. Effect of pore networks on the properties of movable fluids in tight sandstones from the perspective of multi-techniques. J. Petrol. Sci. Eng. 201, 108449. https://doi.org/10.1016/j.petrol.2021.108449 (2021).
Li, P., Zheng, M., Bi, H., Wu, S. & Wang, X. Pore throat structure and fractal characteristics of tight oil sandstone: A case study in the Ordos Basin, China. J. Petrol. Sci. Eng. 149, 665–674. https://doi.org/10.1016/j.petrol.2016.11.015 (2017).
Zhang, Q. et al. Effects of pore-throat structures on the fluid mobility in Chang 7 tight sandstone reservoirs of Longdong area, Ordos basin. Mar. Pet. Geol. 135, 105407. https://doi.org/10.1016/j.marpetgeo.2021.105407 (2022).
Pang, X. et al. Insights into the pore structure and oil mobility in fine-grained sedimentary rocks: the Lucaogou formation in Jimusar Sag, Junggar Basin, China. Mar. Pet. Geol. 137, 105492. https://doi.org/10.1016/j.marpetgeo.2021.105492 (2022).
Xiao, D. et al. Impacts of clay on pore structure, storage and percolation of tight sandstones from the Songliao Basin, china: implications for genetic classification of tight sandstone reservoirs. Fuel 211, 390–404. https://doi.org/10.1016/j.fuel.2017.09.084 (2018).
Qiao, J. et al. Effects of mineralogy on pore structure and fluid flow capacity of deeply buried sandstone reservoirs with a case study in the Junggar basin. J. Petrol. Sci. Eng. 189, 106986. https://doi.org/10.1016/j.petrol.2020.106986 (2020).
Shen, H. et al. New fields, new types and resource potentials of oil-gas exploration in Southern Songliao basin. Acta Petrolei Sinica. 44 (12), 2104–2121. https://doi.org/10.7623/syxb202312007 (2023).
Li, M., Qu, Z., Wang, M. & Ran, W. The influence of micro-heterogeneity on water injection development in low-permeability sandstone oil reservoirs. Minerals 13 (12), 1533. https://doi.org/10.3390/min13121533 (2023).
Wang, T. & Philp, R. Oil families and inferred source rocks of the Woodford–Mississippian tight oil play in northcentral Oklahoma. AAPG Bull. 103 (4), 871–903. https://doi.org/10.1306/09181818049 (2019).
Lin, R. et al. Experimental evaluation of tight sandstones reservoir flow characteristics under CO2-Brine-Rock multiphase interactions: a case study in the Chang 6 layer, Ordos Basin, China. Fuel 309, 122167. https://doi.org/10.1016/j.fuel.2021.122167 (2022).
Wang, Z. et al. Differential development characteristics of secondary pores and effects on pore structure and movable fluid distribution in tight gas sandstones in the lower Permian, Northeastern Ordos Basin, China. Geoenergy Sci. Eng. 224, 211580. https://doi.org/10.1016/j.geoen.2023.211580 (2023).
Xiao, D., Lu, S., Lu, Z., Huang, W. & Gu, M. Combining nuclear magnetic resonance and rate-controlled porosimetry to probe the pore-throat structure of tight sandstones. Pet. Explor. Dev. 43 (6), 1049–1059. https://doi.org/10.1016/S1876-3804(16)30122-7 (2016).
Xiao, D., Lu, Z., Jiang, S. & Lu, S. Comparison and integration of experimental methods to characterize the full-range pore features of tight gas sandstone—A case study in Songliao basin of China. J. Nat. Gas Sci. Eng. 34, 1412–1421. https://doi.org/10.1016/j.jngse.2016.08.029 (2016).
Xiao, D., Lu, S., Yang, J., Zhang, L. & Li, B. Classifying multiscale pores and investigating their relationship with porosity and permeability in tight sandstone gas reservoirs. Energy Fuels. 31 (9), 9188–9200. https://doi.org/10.1021/acs.energyfuels.7b01487 (2017).
Hosseini, M. Estimation of mean pore-size using formation evaluation and Stoneley slowness. J. Nat. Gas Sci. Eng. 33, 898–907. https://doi.org/10.1016/j.jngse.2016.06.029 (2016).
Hosseini, M., Javaherian, A. & Movahed, B. Determination of permeability index using Stoneley slowness analysis, NMR models, and formation evaluations: a case study from a gas reservoir, South of Iran. J. Appl. Geophys. 109, 80–87. https://doi.org/10.1016/j.jappgeo.2014.07.016 (2014).
Hosseini, M. Formation evaluation of a clastic gas reservoir: presentation of a solution to a fundamentally difficult problem. J. Geophys. Eng. 15 (6), 2418–2432. https://doi.org/10.1088/1742-2140/aacee3 (2018).
Baban, A. et al. Robust NMR examination of the three-phase flow dynamics of carbon geosequestration combined with enhanced oil recovery in carbonate formations. Energy Fuels. 38 (3), 2167–2176. https://doi.org/10.1021/acs.energyfuels.3c04674 (2024).
Arif, M., Awan, F., Zhang, H. & Hosseini, M. Coal wettability: a holistic overview of the data sets, influencing factors, and knowledge gaps. Energy Fuels. 38 (16), 15069–15084. https://doi.org/10.1021/acs.energyfuels.4c03052 (2024).
Hosseini, M., Arif, M., Keshavarz, A. & Iglauer, S. Neutron scattering: a subsurface application review. Earth Sci. Rev. 221, 103755. https://doi.org/10.1016/j.earscirev.2021.103755 (2021).
Rota, G. Les objects fractals: B. Mandelbrot, Flammarion, 186 pp. Advances in Mathematics 22(1), 129 (1976). (1975). https://doi.org/10.1016/0001-8708(76)90143-2
Mandelbrot, B. The Fractal Geometry of Nature, Revised and Enlarged Ed (W.H. Freeman and Co., 1983).
Zhao, C. et al. Characterization and fractal characteristics of nano-scale pore structure in shale gas reservoirs: A case study of the deep longmaxi Formation, Zigong region, Southern Sichuan Basin, China. Front. Earth Sci. 12, 1410437. https://doi.org/10.3389/feart.2024.1410437 (2024).
Yao, Y., Liu, D., Tang, D., Tang, S. & Huang, W. Fractal characterization of adsorption-pores of coals from North china: an investigation on CH₄ adsorption capacity of coals. Int. J. Coal Geol. 73 (1), 27–42. https://doi.org/10.1016/j.coal.2007.07.003 (2008).
Anovitz, L. et al. Diagenetic changes in macro- to nano-scale porosity in the St. Peter sandstone: an (ultra) small angle neutron scattering and backscattered electron imaging analysis. Geochim. Cosmochim. Acta. 102, 280–305. https://doi.org/10.1016/j.gca.2012.07.035 (2013).
Zhu, J., Zhang, R., Zhang, Y. & He, F. The fractal characteristics of pore size distribution in cement-based materials and its effect on gas permeability. Sci. Rep. 9, 17191. https://doi.org/10.1038/s41598-019-53828-5 (2019).
Zuo, M. et al. Fractal model of spontaneous imbibition in low-permeability reservoirs coupled with heterogeneity of pore seepage channels and threshold pressure. Pet. Sci. 21 (2), 1002–1017. https://doi.org/10.1016/j.petsci.2023.10.027 (2024).
Zhang, L., Lu, S., Xiao, D. & Li, B. Pore structure characteristics of tight sandstones in the Northern Songliao Basin, China. Mar. Pet. Geol. 88, 170–180. https://doi.org/10.1016/j.marpetgeo.2017.08.005 (2017).
Zhu, G., Wang, X., Bai, X., Lu, J. & Li, J. New exploration fields and resource potential of tight oil in Northern Songliao basin. Acta Petrolei Sinica. 46 (1), 33–47. https://doi.org/10.7623/syxb202501003 (2025).
Li, Z., Bao, Z., Wei, Z., Li, L. & Wang, H. Geochemical features of lacustrine shales in the upper cretaceous Qingshankou formation of Changling Sag, Songliao Basin, Northeast China. Energies 15 (19), 6983. https://doi.org/10.3390/en15196983 (2022).
Cui, Y. et al. Sedimentary characteristics and evolution of shallow-water meandering river delta in Fuyu oil layer, Southern fuxin uplift zone, Songliao basin. J. Palaeogeography. 27 (5), 1207–1226. https://doi.org/10.7605/gdlxb.2025.076 (2025).
Huang, W. et al. Diagenesis and micro-and nano-scale reservoir spaces evolution of tight sandstones in Quantou4 member of Southern Songliao basin. J. China Univ. Petroleum. 20 (1), 11–20. https://doi.org/10.3969/j.issn.1673-5005.2018.01.002 (2018).
Feng, G. et al. Scale-dependent fractal properties and geological factors for the pore structure in shale: insights from field emission scanning electron microscopy and fluid intrusion. Energy Fuels. 37 (21), 16519–16535. https://doi.org/10.1021/acs.energyfuels.3c02833 (2023).
Zhang, T., Li, Z., Lai, F., Adenutsi, C. & You, Q. Effects of the sandstone pore structure on spontaneous imbibition: a systematic experimental investigation based on fractal analysis. Energy Fuels. 36 (1), 382–396. https://doi.org/10.1021/acs.energyfuels.1c03696 (2022).
Li, B. et al. Comparative analysis of CO₂ sequestration potential in shale reservoirs: insights from the longmaxi and Qiongzhusi formations. Minerals 15, 997. https://doi.org/10.3390/min15090997 (2025).
Liu, K. A new method for characterizing the pore-throat structure of tight sandstone based on nuclear magnetic resonance and constant-rate mercury intrusion. Special Oil Gas Reservoirs. 32 (1), 135–143. https://doi.org/10.3969/j.issn.1006-6535.2025.01.016 (2025).
Sun, W. et al. Fractal analysis of pores and the pore structure of the lower cambrian Niutitang shale in Northern Guizhou province: investigations using NMR, SEM and image analyses. Mar. Pet. Geol. 99, 416–428. https://doi.org/10.1016/j.marpetgeo.2018.10.042 (2019).
Bera, A., Shukla, B. & Jogani, D. A perspective review of applications of the computed tomography (CT) scan imaging technique for microscopic reservoir rock characterization. Deep Undergr. Sci. Eng. 1–24. https://doi.org/10.1002/dug2.12138 (2025).
Sing, K. Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984). Pure Appl. Chem. 57 (4), 603–619. https://doi.org/10.1351/pac198557040603 (1985).
Yang, F., Ning, Z. & Liu, H. Fractal characteristics of shales from a shale gas reservoir in the Sichuan basin. China Fuel. 115, 378–384. https://doi.org/10.1016/j.fuel.2013.07.040 (2014).
Wang, M., Xue, H., Tian, S., Wilkins, R. & Wang, Z. Fractal characteristics of upper cretaceous lacustrine shale from the Songliao Basin, NE China. Mar. Pet. Geol. 67, 144–153. https://doi.org/10.1016/j.marpetgeo.2015.05.011 (2015).
Zhang, J. et al. Pore structure and fractal characteristics of coal-bearing cretaceous Nenjiang shales from Songliao Basin, Northeast China. Nat. Gas Geoscience. 35 (1), 119–132. https://doi.org/10.11764/j.issn.1672-1926.2023.07.018 (2024).
Li, L. et al. Microscopic pore structure and fractal characteristics of tight sandstone gas reservoir: A case study of Denglouku formation in Changling gas Field, Songliao basin. Nat. Gas Geoscience. 34 (6), 1039–1052. https://doi.org/10.11764/j.issn.1672-1926.2023.02.002 (2023).
Lai, J. et al. Fractal analysis of tight Shaly sandstones using nuclear magnetic resonance measurements. AAPG Bull. 102 (2), 175–193. https://doi.org/10.1306/0425171609817007 (2018).
Zhang, J., Tang, Y., He, D., Sun, P. & Zou, X. Full-scale nanopore system and fractal characteristics of clay-rich lacustrine shale combining FE-SEM, nano-CT, gas adsorption and mercury intrusion porosimetry. Appl. Clay Sci. 196, 105758. https://doi.org/10.1016/j.clay.2020.105758 (2020).
Wang, R. et al. Identification of ultra-low permeability sandstone reservoir nano pore-throat by multi-scale CT imaging technique. Progress Geophys. 35 (1), 188–196. https://doi.org/10.6038/pg2020CC0336 (2020).
Su, Y. et al. Pore structure and fluid distribution of tight sandstone by the combined use of SEM, MICP and X-ray micro-CT. J. Petrol. Sci. Eng. 208 (E), 109241. https://doi.org/10.1016/j.petrol.2021.109241 (2022).
Lai, J. et al. Insight into the pore structure of tight sandstones using NMR and HPMI measurements. Energy Fuels. 30 (12), 10200–10214. https://doi.org/10.1021/acs.energyfuels.6b01982 (2016).
Wang, J., Wu, S., Li, Q., Zhang, J. & Guo, Q. Characterization of the pore-throat size of tight oil reservoirs and its control on reservoir physical properties: A case study of the triassic tight sandstone of the sediment gravity flow in the Ordos Basin, China. J. Petrol. Sci. Eng. 186, 106701. https://doi.org/10.1016/j.petrol.2019.106701 (2020).
Gong, Y. & Liu, K. Pore throat size distribution and oiliness of tight sands-A case study of the Southern Songliao Basin, China. J. Petrol. Sci. Eng. 184, 106508. https://doi.org/10.1016/j.petrol.2019.106508 (2020).
Lai, J. et al. Fan, X. A review on pore structure characterization in tight sandstones. Earth Sci. Rev. 177, 436–457. https://doi.org/10.1016/j.earscirev.2017.12.003 (2018).
Qiao, J. et al. Insights into the pore structure and implications for fluid flow capacity of tight gas sandstone: A case study in the upper paleozoic of the Ordos basin. Mar. Pet. Geol. 118, 104439. https://doi.org/10.1016/j.marpetgeo.2020.104439 (2020).
Qu, Y. et al. Impacts of pore-throat spaces on movable fluid: implications for Understanding the tight oil exploitation process. Mar. Pet. Geol. 137, 105509. https://doi.org/10.1016/j.marpetgeo.2021.105509 (2022).
Liu, Z., Li, C., Lu, Y., Wang, Y. & Huang, J. Fluid occurrence state and permeability evaluation of low-permeability sandstone based on pore structure characterization. J. Jilin Univ. (Earth Sci. Edition). 54 (4), 1124–1136. https://doi.org/10.13278/j.cnki.jjuese.20230056 (2024).
Funding
This research was funded by the Research on ballast stone demonstration project in Daqingzijing Oilfield (2023YQX10208); the Research on the key technology of chemical flooding to enhance oil recovery in low permeability/tight reservoir (2023ZZ17YJ04); the Chongqing Municipal Education Commission Science and Technology Research Plan Project (KJQN202301537); the General Program of Chongqing Natural Science Foundation (CSTB2022NSCQ-MSX1423); the General Program of Chongqing Natural Science Foundation (CSTB2025NSCQ-GPX0934).
Author information
Authors and Affiliations
Contributions
H.L.W., Z.C.L.,S.J.H. and F.F.F. wrote the main manuscript text, and H.X.W., H.R.W., Q.L.,Q.G., T.T.W., Y.H.L, Y.Y. and C.X.B. prepared Figs. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18. All authors reviewed the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
About this article
Cite this article
Wang, H., Li, Z., He, S. et al. Influencing factors of oil-bearing capacity in tight sandstones based on pore structure characterization: a case study of the Fuyu reservoir in the Xinmiao oilfield, Southern Songliao Basin. Sci Rep (2025). https://doi.org/10.1038/s41598-025-34053-9
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-025-34053-9