Abstract
Unconventional reservoirs are generally characterized by low matrix porosity and permeability, in which natural fractures are important factors for gas production. In this study, we analyzed characteristics of natural fractures, and their influencing factors based on observations from outcrops, cores and image logs. The orientations of natural fractures were mainly in the ∼N-S, WNW-ESE and NE-SW directions with relatively high fracture dip angles. Fracture densities were calculated based on fracture measurements within cores, indicating that natural fractures were not well-developed in the Benxi-Upper Shihezi Formations of Linxing Block. The majority of natural fractures were open fractures and unfilled. According to the characteristics of fracture sets and tectonic evolution of the study area, natural fractures in the Linxing Block were mainly formed in the Yanshanian and Himalayan periods. The lithology and layer thickness influenced the development of natural fractures, and more natural fractures were generated in carbonate rocks and thin layers in the study area. In addition, in the Linxing Block, natural fractures with ∼N-S-trending strikes contributed little to the overall subsurface fluid flow under the present-day stress state. These study results provide a geological basis for gas exploration and development in the Linxing unconventional reservoirs of Ordos Basin.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Aadnoy B S, Bell J S (1998). Classification of drilling-induced fractures and their relationship to in-situ stress directions. Log Anal, 39(6): 27–42
Aydin A (2000). Fractures, faults, and hydrocarbon entrapment, migration, and flow. Mar Pet Geol, 17(7): 797–814
Bhandakkar P, Siddhamshetty P, Sang-Il Kwon J (2020). Numerical study of the effect of propped surface area and fracture conductivity on shale gas production: application for multi-size proppant pumping schedule design. J Nat Gas Sci Eng, 79: 103349
Bowker K A (2007). Barnett shale gas production, Fort Worth Basin: issues and discussion. AAPG Bull, 91(4): 523–533
Buller D, Hughes S N, Market J, Petre J E, Spain D R, Odumosu T (2010). Petrophysical evaluation for enhancing hydraulic stimulation in horizontal shale gas wells. Society of Petroleum Engineers
Canady W, Market J, (2008). Fracture characterization by borehole logging methods. Society of Petrophysicists and Well-Log Analysts, SPWLA-2008-AAA (1-12)
Dahi-Taleghani A, Olson J E (2011). Numerical modeling of multi-stranded-hydraulic-fracture propagation: accounting for the interaction between induced and natural fractures. Society of Petroleum Engineers, 16(3): 575–581
Folkestad A, Veselovsky Z, Roberts P (2012). Utilising borehole image logs to interpret delta to estuarine system: a case study of the subsurface Lower Jurassic Cook Formation in the Norwegian northern North Sea. Mar Pet Geol, 29(1): 255–275
Fossen H (2010). Structural Geology. Cambridge: Cambridge University Press
Gale J F W, Laubach S E, Olson J E, Eichhuble P, Fall A (2014). Natural fractures in shale: a review and new observations. AAPG Bull, 98 (11): 2165–2216
Gale J F W, Reed R M, Holder J (2007). Natural fractures in the Barnett Shale and their importance for hydraulic fracture treatments. AAPG Bull, 91(4): 603–622
Gao X D, Wang Y B, Ni X M, Li Y, Wu X, Zhao S H, Yu Y (2018). Recovery of tectonic traces and its influence on coalbed methane reservoirs: a case study in the Linxing area, eastern Ordos Basin, China. J Nat Gas Sci Eng, 56: 414–427
Hall S A, Kendall J M, Barkved O I (2002). Fractured reservoir characterization using P-wave AVOA analysis of 3D OBC data. Leading Edge (Tulsa Okla), 21(8): 777–781
Hancock P L (1985). Brittle microtectonics: principles and practice. J Struct Geol, 7(3–4): 437–457
Harstad H, Teufel L W, Lorenz J C (1995). Characterization and simulation of naturally fractured tight gas sandstones. Society of Petroleum Engineers
Hennings P H, Olson J E, Thompson L B (2000). Combining outcrop data and three-dimensional structural models to characterize fractured reservoir: an example from Wyoming. AAPG Bull, 84: 830–849
Ju W, Niu X B, Feng S B, You Y, Xu K, Wang G, Xu H R (2020). Present-day in-situ stress field within the Yanchang Formation tight oil reservoir of Ordos Basin, central China. J Petrol Sci Eng, 187: 106809
Ju W, Shen J, Qin Y, Meng S Z, Wu C F, Shen Y L, Yang Z B, Li G Z, Li C (2017). In-situ stress state in the Linxing region, eastern Ordos Basin, China: implications for unconventional gas exploration and production. Mar Pet Geol, 86: 66–78
Ju W, Sun W F (2016). Tectonic fractures in the Lower Cretaceous Xiagou Formation of Qingxi Oldfield, Jiuxi Basin, NW China. Part one: characteristics and controlling factors. J Petrol Sci Eng, 146: 617–625
Ju W, Sun W F, Hou G T (2015). Insights into the tectonic fractures in the Yanchang Formation interbedded sandstone-mudstone of the Ordos Basin based on core data and geomechanical models. Acta Geol Sin, 89(6): 1986–1997
Ju W, Wang J L, Fang H H, Sun W F (2019). Paleotectonic stress field modeling and prediction of natural fractures in the Lower Silurian Longmaxi shale reservoirs, Nanchuan region, South China. Mar Pet Geol, 100: 20–30
Ju W, Wang K, Hou G T, Sun W F, Yu X (2018). Prediction of natural fractures in the Lower Jurassic Ahe Formation of the Dibei Gasfield, Kuqa Depression, Tarim Basin, NW China. Geosci J, 22(2): 241–252
Laubach S E, Marrett R A, Olson J E, Scott A R (1998). Characteristics and origins of coal cleat: a review. Int J Coal Geol, 35(1–4): 175–207
Laubach S E, Olson J E, Gross M R (2009). Mechanical and fracture stratigraphy. AAPG Bull, 93(11): 1413–1426
Li Y, Tang D Z, Wu P, Niu X L, Wang K, Qiao P, Wang Z S (2016). Continuous unconventional natural gas accumulation of Carboniferous-Permian coal-bearing strata in the Linxing area, northeastern Ordos Basin, China. J Nat Gas Sci Eng, 36: 314–327
Liu C Y, Zhao H G, Sun Y Z (2009). Tectonic background of Ordos Basin and its controlling role for basin evolution and energy mineral deposits. Energy Exploration and Exploitation, 27(1): 15–27
Marrett R, Ortega O J, Kelsey C M (1999). Extent of power-law scaling for natural fractures in rock. Geology, 27(9): 799–802
McGinnis R N, Ferrill D A, Morris A P, Smart K J, Lehrmann D (2017). Mechanical stratigraphic controls on natural fracture spacing and penetration. J Struct Geol, 95: 160–170
Narr W (1991). Fracture density in the deep subsurface: techniques with application to Point Arguello Oil Field. AAPG Bull, 75: 1300–1323
Narr W, Suppe J (1991). Joint spacing in sedimentary rocks. J Struct Geol, 13(9): 1037–1048
Nelson R A (2001). Geologic Analysis of Naturally Fractured Reservoirs. 2nd ed. Massachusetts: Gulf Professional Publishing
Olson J E, Laubach S E, Lander R H (2009). Natural fracture characterization in tight gas sandstones: integrating mechanics and diagenesis. AAPG Bull, 93(11): 1535–1549
Qu H Z, Zhang F X, Wang Z Y, Yang X T, Liu H T, Ba D, Wang X (2016). Quantitative fracture evaluation method based on core-image logging: a case study of Cretaceous Bashijiqike Formation in ks2 well area, Kuqa depression, Tarim Basin, NW China. Pet Explor Dev, 43(3): 465–473
Rajabi M, Sherkati S, Bohloli B, Tingay M (2010). Subsurface fracture analysis and determination of in-situ stress direction using FMI logs: an example from the Santonian carbonates (Ilam Formation) in the Abadan Plain, Iran. Tectonophysics, 492(1–4): 192–200
Sibson R H (1996). Structural permeability of fluid-driven fault-fracture meshes. J Struct Geol, 18(8): 1031–1042
Shen J, Qin Y, Zhang B, Li G Z, Shen Y L (2018). Superimposing gas-bearing system in coal measures and its compatibility in Linxing block, east Ordos Basin. Journal of China Coal Society, 43(6): 1614–1619 (in Chinese)
Shen Y L, Qin Y, Wang G, Guo Y H, Shen J, Gu J Y, Xiao Q, Zhang T, Zhang C L, Tong G C (2017). Sedimentary control on the formation of a multi-superimposed gas system in the development of key layers in the sequence framework. Mar Pet Geol, 88: 268–281
Shu Y, Lin Y X, Liu Y, Yu Z Y (2019). Control of magmatism on gas accumulation in Linxing area, Ordos Basin, NW China: evidence from fluid inclusions. J Petrol Sci Eng, 180: 1077–1087
Siddhamshetty P, Bhandakkar P, Kwon J S (2020). Enhancing total fracture surface area in naturally fractured unconventional reservoirs via model predictive control. J Petrol Sci Eng, 184: 106525
Speight J G (2019). Natural Gas: A Basin Handbook. 2nd ed. Massachusetts: Gulf Professional Publishing
Tingay M, Reinecker J, Muller B, (2008). Borehole breakout and drilling-induced fracture analysis from image logs. World Stress Map Project Guidelines: Image Logs, 1–8
van Golf-Racht T D (1982). Fundamentals of Fractured Reservoir Engineering. New York: Elsevier Scientific Publishing Company
Wang X Y, Zhang Q L, Wang L S, Ge R F, Chen J (2010). Structural features and tectonic stress fields of the Mesozoic and Cenozoic in the eastern margin of the Ordos Basin. Geological Bulletin of China, 29 (8): 1168–1176 (in Chinese)
Wang Y C (1992). Fractured Tight Oil and Gas Reservoirs. Beijing: Geological Publishing House
Weniger S, Weniger P, Littke R (2016). Characterizing coal cleats from optical measurements for CBM evaluation. Int J Coal Geol, (154–155): 176–192
Wu K, Olson J E (2016). Numerical investigation of complex hydraulic-fracture development in naturally fractured reservoirs. SPE Prod Oper, 31(4): 300
Xie Y G, Sun X Y, Wan H, Duan C J, Chen Q, Yu Y J (2017). A study of shallow-water deltaic facies from Upper Shihezi Formation in Linxing area, Ordos Basin. Unconventional Oil and Gas, 4(2): 13–21 (in Chinese)
Yang Y T, Li W, Ma L (2005). Tectonic and stratigraphic controls of hydrocarbon systems in the Ordos Basin: a multicycle cratonic basin in central China. AAPG Bull, 89(2): 255–269
Zeng L B (2008). Formation and Distribution of Natural Fractures in Low-permeability Sandstone Reservoirs. Beijing: Science Press (in Chinese)
Zeng L B, Li X Y (2009). Fractures in sandstone reservoirs with ultra-low permeability: a case study of the Upper Triassic Yanchang Formation in the Ordos Basin, China. AAPG Bull, 93(4): 461–477
Zhao G C, Sun M, Wilde S A, Li S Z (2005). Late Archean to Paleoproterozoic evolution of the North China Craton: key issues revisited. Precambrian Res, 136(2): 177–202
Zhao M W, Hans J B, Hans A (1996). Thermal and tectonic history of the Ordos Basin, China: Evidence from apatite fission track analysis, vitrinite reflectance, and K-Ar dating. AAPG Bull, 80(7): 1110–1134
Zoback M D, Barton C A, Brudy M, Castillo D A, Finkbeiner T, Grollimund B R, Moos D B, Peska P, Ward C D, Wiprut D J (2003). Determination of stress orientation and magnitude in deep wells. Int J Rock Mech Min Sci, 40(7–8): 1049–1076
Acknowledgements
Many thanks to the financial support from National Natural Science Foundation of China (Grant Nos. 41702130 and 41872171), National Science and Technology Major Project (2016ZX05066), and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ju, W., Shen, J., Li, C. et al. Natural fractures within unconventional reservoirs of Linxing Block, eastern Ordos Basin, central China. Front. Earth Sci. 14, 770–782 (2020). https://doi.org/10.1007/s11707-020-0831-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11707-020-0831-3