Effects of mechanical layering on hydraulic fracturing in shale gas reservoirs based on numerical models

  • Wei Ju
  • Caifang Wu
  • Weifeng Sun
Original Paper


Generally, induced hydraulic fractures are generated by fluid overpressure and are used to increase reservoir permeability through forming interconnected fracture systems. However, in heterogeneous and anisotropic rocks, many hydraulic fractures may become arrested or offset at layer contacts under certain conditions and do not form vertically connected fracture networks. Mechanical layering is an important factor causing anisotropy in sedimentary layers. Hence, in this study, with a shale gas reservoir case study in the Longmaxi Formation in the southeastern Chongqing region, Sichuan Basin, we present results from several numerical models to gain quantitative insights into the effects of mechanical layering on hydraulic fracturing. Results showed that the fractured area caused by hydraulic fracturing indicated a linear relationship with the neighboring layer’s Young’s modulus. An increase of the neighboring layer’s Young’s modulus resulted in better hydraulic fracturing effects. In addition, the contact between two neighboring layers is regarded as a zone with thickness and mechanical properties, which also influences the effects of hydraulic fracturing in reservoirs. The initial hydraulic fracture was unable to propagate into neighboring layers under a relatively low contact’s Young’s modulus. When associated local tensile stresses exceeded the rock strength, hydraulic fractures propagated into neighboring layers. Moreover, with the contact’s Young’s modulus becoming higher, the fractured area increased rapidly first, then slowly and finally became stable.


Hydraulic fracturing Numerical models Longmaxi Formation Mechanical layering Shale gas reservoir Chongqing region Sichuan Basin 



We would like to express our gratitude to Dr. Barry Jay Katz and the anonymous reviewers for offering constructive suggestions and comments which improved this manuscript in many aspects.

Funding information

This work was financially supported by the Fundamental Research Funds for the Central Universities (2018QNA44).


  1. Aguilera R (2000) Well test analysis of multi-layered naturally fractured reservoirs. J Can Pet Technol 39:31–37Google Scholar
  2. Al-Busaidi A, Hazzard JF, Young RP (2005) Distinct element modeling of hydraulically fractured Lac du Bonnet granite. J Geophys Res 110:1–14CrossRefGoogle Scholar
  3. Bonafede M, Rivalta E (1999) The tensile dislocation problem in a layered elastic medium. Geophys J Int 136:341–356CrossRefGoogle Scholar
  4. Bowker KA (2007) Barnett shale gas production, Fort Worth Basin: issues and discussion. AAPG Bull 91:523–533CrossRefGoogle Scholar
  5. Cheng YM, Lee WJ, McVay DA (2007) A new approach for reliable estimation of hydraulic fracture properties using elliptical flow data in tight gas wells. SPE Reserv Eval Eng 12:254–262CrossRefGoogle Scholar
  6. Cooke ML, Underwood CA (2001) Fracture termination and step-over at bedding interface due to frictional slip and interface opening. J Struct Geol 23:223–238CrossRefGoogle Scholar
  7. Daneshy AA (2003) Off-balance growth: a new concept in hydraulic fracturing. J Pet Technol 55:78–85CrossRefGoogle Scholar
  8. Ding WL, Fan TL, Yu BS, Huang XB, Liu C (2012) Ordovician carbonate reservoir fracture characteristics and fracture distribution forecasting in the Tazhong area of Tarim Basin, Northwest China. J Pet Sci Eng 86–87:62–70CrossRefGoogle Scholar
  9. Dong DZ, Zou CN, Yang H, Wang YM, Li XJ, Chen GS, Wang SQ, Lv ZG, Huang YB (2012) Progress and prospects of shale gas exploration and development in China. Acta Petrol Sin 33:107–114 (in Chinese with English abstract)CrossRefGoogle Scholar
  10. Economides MJ, Nolte KG (2000) Reservoir stimulation, (3rd edition) edn. John Wiley and Sons, New York, p 792Google Scholar
  11. Fan WF, Hou DJ, Liang Y (2015) Comparative study on reservoir forming conditions between Niutitang and Longmaxi Formation of shale gas in South China: taking Southeast Chongqing area for example. Science Technology and Engineering 15:13–22 (in Chinese with English abstract)Google Scholar
  12. Flekkoy EG, Malthe-Sorenssen A, Jamtveit B (2002) Modeling hydrofracture. J Geophys Res 107:1–11CrossRefGoogle Scholar
  13. Geshi N, Kusumoto S, Gudmundsson A (2012) Effects of mechanical layering of host rocks on dike growth and arrest. J Volcanol Geotherm Res 223–224:74–82CrossRefGoogle Scholar
  14. Guan QZ, Dong DZ, Wang SF, Huang JL, Wang YM, Lu H, Zhang CC (2016) Preliminary study on shale gas microreservoir characteristics of the Lower Silurian Longmaxi Formation in the southern Sichuan Basin, China. J Nat Gas Sci Eng 31:382–395CrossRefGoogle Scholar
  15. Gudmundsson A (2011) Rock fractures in geological processes. Cambridge University Press, Cambridge, p 578CrossRefGoogle Scholar
  16. Gudmundsson A, Brenner SL (2001) How hydrofractures become arrested. Terra Nova 13:456–462CrossRefGoogle Scholar
  17. Guo P, Yao LH, Ren DS (2016) Simulation of three-dimensional tectonic stress fields and quantitative prediction of tectonic fracture within the Damintun Depression, Liaohe Basin, northeast China. J Struct Geol 86:211–223CrossRefGoogle Scholar
  18. Guo TL, Zhang HR (2014) Formation and enrichment mode of Jiaoshiba shale gas field, Sichuan Basin. Pet Explor Dev 41:31–40CrossRefGoogle Scholar
  19. Guo XS, Hu DF, Wen ZD, Liu RB (2014) Major factors controlling the accumulation and high productivity in marine shale gas in the Lower Paleozoic of Sichuan Basin and its periphery: a case study of the Wufeng-Longmaxi Formation of Jiaoshiba. Geol China 41:893–901 (in Chinese with English abstract)Google Scholar
  20. Helgeson DE, Aydin A (1991) Characteristics of joint propagation across layer interfaces in sedimentary rocks. J Struct Geol 13:897–911CrossRefGoogle Scholar
  21. Hossain MM, Rahman MK (2008) Numerical simulation of complex fracture growth during tight reservoir stimulation by hydraulic fracturing. J Pet Sci Eng 60:86–104CrossRefGoogle Scholar
  22. Hou GT, Kusky TM, Wang CC, Wang YX (2010) Mechanics of the giant radiating Mackenzie dyke swarm: a palaeostress field modeling. J Geophys Res 115:1–14CrossRefGoogle Scholar
  23. Hutchinson JW (1996) Stresses and failure modes in thin films and multilayers. Notes for a DCAMM course. Technical University of Denmark, Lyngby, pp 1–45Google Scholar
  24. Hutchinson JW, Suo Z (1992) Mixed-mode cracking in layered materials. Adv Appl Mech 29:63–191CrossRefGoogle Scholar
  25. Ju W, Hou GT, Hari KR (2013) Mechanics of mafic dyke swarms in the Deccan Large Igneous Province: Palaeostress field modelling. J Geodyn 66:79–91CrossRefGoogle Scholar
  26. Ju W, Hou GT, Zhang B (2014) Insights into the damage zones in fault-bend folds from geomechanical models and field data. Tectonophysics 610:182–194CrossRefGoogle Scholar
  27. Ju W, Sun WF (2016) Tectonic fractures in the Lower Cretaceous Xiagou Formation of Qingxi Oilfield, Jiuxi Basin, NW China. Part two: numerical simulation of tectonic stress field and prediction of tectonic fractures. J Pet Sci Eng 146:626–636CrossRefGoogle Scholar
  28. Ju W, Sun WF, Hou GT (2015) Insights into the tectonic fractures in the Yanchang Formation interbeded sandstone-mudstone of the Ordos Basin based on core data and geomechanical models. Acta Geological Sinica (English Edition) 89:1986–1997CrossRefGoogle Scholar
  29. Kim JW, Bhowmick S, Hermann I, Lawn BR (2006) Transverse fracture in brittle bilayers: relevance for failure of all-ceramic dental crowns. J Biomed Mater Res B Appl Biomater 79B:58–65CrossRefGoogle Scholar
  30. Larsen B, Gudmundsson A, Grunnaleite I, Sælen G, Talbot MR, Buckley SJ (2010) Effects of sedimentary interfaces on fracture pattern, linkage, and cluster formation in peritidal carbonate rocks. Mar Pet Geol 27:1531–1550CrossRefGoogle Scholar
  31. Li XT, Shi WR, Guo MY, Liu X, Zhao HY, Chen X, Ren Y, Shi YH (2014) Characteristics of marine shale gas reservoirs in Jiaoshiba area of Fuling shale gas field. Journal of Oil and Gas Technology 36:11–15 (in Chinese with English abstract)Google Scholar
  32. Liu RB (2015) Typical features of the first giant shale gas field in China. Nat Gas Geosci 26:1488–1498 (in Chinese with English abstract)Google Scholar
  33. Mahrer KD (1999) A review and perspective on far-field hydraulic fracture geometry studies. J Pet Sci Eng 24:13–28CrossRefGoogle Scholar
  34. Nie HK, Zhang JC, Zhang PX, Song XW (2009) Shale gas reservoir characteristics of Barnett Shale Gas Reservoir in Fort Worth Basin. Geological Science and Technology Information 28:87–93 (in Chinese with English abstract)Google Scholar
  35. Pan L, Xiao XM, Tian H, Zhou Q, Cheng P (2016) Geological models of gas in place of the Longmaxi shale in Southeast Chongqing, South China. Mar Pet Geol 73:433–444CrossRefGoogle Scholar
  36. Petrie ES, Evans JP (2016) Modeling strain across mechanical sedimentary lithologic interfaces: geomechanical models derived from outcrop analysis. Bull Can Petrol Geol 64(4):477–494CrossRefGoogle Scholar
  37. Petrie ES, Jeppson TN, Evans JP (2012) Predicting rock strength variability across stratigraphic interfaces in caprock lithologies at depth: correlation between outcrop and subsurface. Environ Geosci 19(4):125–142CrossRefGoogle Scholar
  38. Philipp SL, Afsar F, Gudmundsson A (2013) Effects of mechanical layering on hydrofracture emplacement and fluid transport in reservoirs. Front Earth Sci 1:1–19CrossRefGoogle Scholar
  39. Pollard DD, Aydin A (1988) Progress in understanding jointing over the past century. Geol Soc Am Bull 100:1181–1204CrossRefGoogle Scholar
  40. Shi M, Yu BS, Xue ZP, Wu JS, Yuan Y (2015) Pore characteristics of organic-rich shales with high thermal maturity: a case study of the Longmaxi gas shale reservoirs from well Yuyue-1 in southeastern Chongqing, China. J Nat Gas Sci Eng 26:948–959CrossRefGoogle Scholar
  41. Tan LY, Xu Y, Li DH, Cheng LJ, Zeng CL (2015) Geological condition of shale gas accumulation and favorable area prediction for the Wufeng-Longmaxi Formation in Southeastern Chongqing. Acta Geol Sin 89:1308–1317 (in Chinese with English abstract)CrossRefGoogle Scholar
  42. Wangen M (2011) Finite element modeling of hydraulic fracturing on a reservoir scale in 2D. J Pet Sci Eng 77:274–285CrossRefGoogle Scholar
  43. Warlick D (2006) Gas shale and CBM development in North America. Oil and Gas Financial Journal 3:1–5Google Scholar
  44. Yew CH, Weng XW (2015) Mechanics of hydraulic fracturing, 2nd edn. Gulf Publishing, Houston, p 234Google Scholar
  45. Zang A, Stephansson O (2010) Stress field of the Earth’s crust. Springer, Berlin, p 322CrossRefGoogle Scholar
  46. Zeng WT, Zhang JC, Ding WL, Zhao S, Zhang YQ, Liu ZJ, Jiu K (2013a) Fracture development in Paleozoic shale of Chongqing area (South China). Part one: fracture characteristics and comparative analysis of main controlling factors. J Asian Earth Sci 75:251–266CrossRefGoogle Scholar
  47. Zeng WT, Ding WL, Zhang JC, Zhang YQ, Guo L, Jiu K, Li YF (2013b) Fracture development in Paleozoic shale of Chongqing area (South China). Part two: numerical simulation of tectonic stress field and prediction of fractures distribution. J Asian Earth Sci 75:267–279CrossRefGoogle Scholar
  48. Zhang JC, Jiang SL, Tang X, Zhang PX, Tang Y, Jing TY (2009) Accumulation types and resources characteristics of shale gas in China. Nat Gas Ind 29:109–114 (in Chinese with English abstract)Google Scholar
  49. Zhang JC, Li YX, Nie HK, Long PY, Tang Y, Tang X, Jiang WL (2010) Geologic setting and drilling effect of the shale cored well Yuye-1, Pengshui County of Chongqing. Nat Gas Ind 30:114–118 (in Chinese with English abstract)Google Scholar
  50. Zhang Q, Liu RH, Pang ZL, Lin W, Bai WH, Wang HY (2016) Characterization of microscopic pore structures in Lower Silurian black shale (S1l), southeastern Chongqing, China. Mar Pet Geol 71:250–259CrossRefGoogle Scholar
  51. Zhang X, Jeffrey RG, Thiercelin M (2007) Deflection and propagation of fluid-driven fractures at frictional bedding interfaces: a numerical investigation. J Struct Geol 29:396–410CrossRefGoogle Scholar
  52. Zou CN, Yang Z, Dai JX, Dong DZ, Zhang BM, Wang YM, Deng SH, Huang JL, Liu KY, Yang C, Wei GQ, Pan SQ (2015) The characteristics and significance of conventional and unconventional Sinian-Silurian gas systems in the Sichuan Basin, central China. Mar Pet Geol 64:386–402CrossRefGoogle Scholar

Copyright information

© Saudi Society for Geosciences 2018

Authors and Affiliations

  1. 1.Key Laboratory of Coalbed Methane Resources and Reservoir Formation ProcessMinistry of EducationXuzhouChina
  2. 2.School of Resources and GeosciencesChina University of Mining and TechnologyXuzhouChina

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