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Experimental Study on The Hydraulic Fracture Propagation In Shale


Affiliations
1 School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province - 454000, China
2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei - 430071, China
3 Machay School of Earth Sciences and Engineering, University of Nevada, Reno, NV, United States
 

To realize the control on geometry of fracture network and improve the individual well production of shale gas reservoirs, hydraulic fracturing simulation tests of shale outcrops for horizontal well were carried out. This was based on an established true triaxial hydraulic fracturing simulation test system, to analyse the propagation and formation of a complex fracture network. The results show that the typical severe fluctuation of pump pressure during extension, is an obvious feature of hydraulic fracturing by Stimulated Reservoir Volume (SRV). Due to the large size and abundant natural fractures in shale specimens, the acoustic emission (AE) energy is weak during propagation of hydraulic fractures. However, fracture propagation can still be effectively determined to some extent, although relatively few AE events are detected. Hydraulic fractures from horizontal well initiate approximately along the maximal in situ stress. But the fractures gradually deviate from the orientation when extending. Branching, re-orientation or penetrating bedding planes and then interconnecting with natural fractures or weak beddings are the main mechanisms of the formation of complicated fracture networks.

Keywords

Fracture Propagation, Fracture Network, Hydraulic Fracturing, Shale, Stimulated Reservoir Volume.
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  • Clarkson, C. R et al., Pore structure characterization of North American shale gas reservoirs using USANS/SANS, gas adsorption, and mercury intrusion. Fuel, 2013, 103, 606–616.

  • Zou, C. et al., Geological characteristics, formation mechanism and resource potential of shale gas in China. Petrol. Exp. Dev., 2010, 37(6), 641–653.

  • Cipolla, C. L. et al., The relationship between fracture complexity, reservoir properties, and fracture treatment design. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2008.

  • King, G. E., Thirty years of gas shale fracturing: what have we learned?. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2010.

  • Britt, L. K. and Schoeffler, J., The geomechanics of a shale play: what makes a shale prospective. In SPE Eastern Regional Meeting, Society of Petroleum Engineers, 2009.

  • Rickman, R. et al., A practical use of shale petrophysics for stimulation design optimization: All shale plays are not clones of the Barnett Shale. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2008.

  • Wang, G.-C., Jiang, R.-Z. and Xu, J.-C., Analysis and advice for shale gas development. Complex Hydrocarbon Res., 2012, 5(2), 10–14.

  • Xie, H.-P. et al., Unconventional theories and strategies for fracturing treatments of shale gas strata. J. Sichuan Univ. (Engineering science edition), 2012, 44(6), 1–6.

  • Du, C., Study on theoretics of hydraulic fracturing in coal bed and applicatons. Ph D thesis, China University of Mining and Technology, 2008.

  • Bingxiang, H., Research on theory and application of hydraulic fracture weakening for coal-rock mass. J. China Coal Soc., 2010, 35(10), 1765–1766.

  • Beugelsdijk, L. J. L., De Pater, C. J. and Sato, K., Experimental hydraulic fracture propagation in a multi-fractured medium. In SPE Asia Pacific Conference on Integrated Modelling for Asset Management, Society of Petroleum Engineers, 2000.

  • Zhou, J. et al., Experiment of propagation mechanism of hydraulic fracture in multi-fracture reservoir. J. Univ. Petrol. China (edition of natural science), 2008, 32(4), 51–54.

  • Casas, L. A. et al., Laboratory hydraulic fracturing test on a rock with artificial discontinuities. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2006.

  • Damani, A. et al., Mapping of hydraulic fractures under triaxial stress conditions in laboratory experiments using acoustic emissions. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2012.

  • Zhou, J., Jin, Y. and Chen, M., Experimental investigation of hydraulic fracturing in random naturally fractured blocks. Int. J. Rock Mech. Min. Sci., 2010, 47(7), 1193–1199.

  • Zhou, J. et al., Analysis of fracture propagation behavior and fracture geometry using a tri-axial fracturing system in naturally fractured reservoirs. Int. J. Rock Mech. Min. Sci., 2008, 45(7), 1143–1152.

  • Sarout, J. et al., Shale dynamic properties and anisotropy under triaxial loading: Experimental and theoretical investigations. Phys. Chem. Earth, Parts A/B/C, 2007, 32(8), 896–906.

  • Heng, S. et al., Experimental research on anisotropic properties of shale. Rock and Soil Mech., 2015, 36(3), 609–616.

  • Heng, S. et al., Experimental and theoretical study of the anisotropic properties of shale. Int. J. Rock Mech. Mining Sci., 2015, 74, 58–68.

  • Weng, X. et al., Modelling of hydraulic-fracture-network propagation in a naturally fractured formation. SPE Prod. Oper., 2011, 26(04), 368–380.

  • Xu, Z. et al., Physical simulation of hydraulic fracturing of shale gas reservoir. Petroleum Drilling Techniques, 2013, 41(2), 70–74.

  • Yushi, Z. et al., Experimental investigation into hydraulic fracture network propagation in gas shales using CT scanning technology. Rock Mech. Rock Eng., 2016, 49(1), 33–45.

  • Guo, T. et al., Experimental study of hydraulic fracturing for shale by stimulated reservoir volume. Fuel, 2014, 128, 373–380.

  • Zhang, S. et al., Fracture propagation mechanism experiment of hydraulic fracturing in natural shale. Acta Petrolei Sin., 2014, 35(3), 496–503, 518.

  • Zhang, Y. et al., A study of hydraulic fracture propagation for shale fracturing. Sci. Technol. Eng., 2015, 15(5), 11–16.

  • Guo, Y. et al., Research on hydraulic fracturing physical simulation of shale and fracture characterization methods. Chin. J. Rock Mech. Eng., 2014, 33(1), 52–59.

  • Heng, S. et al., Experimental study on hydraulic fracture geometry of shale. Chin. J. Geotechn. Eng., 2013, 36(7), 1243–1251.

  • Hou, B. et al., Fracturing mechanism of shale gas reservoir with variable pump rates. Chin. J. Geotech. Eng., 2014, 36(11), 2149–2152.

  • Rickman, R. et al., A practical use of shale petrophysics for stimulation design optimization: All shale plays are not clones of the Barnett Shale. In SPE Annual Technical Conference and Exhibition, Society of Petroleum Engineers, 2008.

  • Goktan, R. M. and Yilmaz, N. G., A new methodology for the analysis of the relationship between rock brittleness index and drag pick cutting efficiency. J. South Afr. Inst. Min. Metallur., 2005, 105(10), 727.

  • Yoshinaka, R. et al., Practical determination of mechanical design parameters of intact rock considering scale effect. Eng. Geol., 2008, 96(3), 173–186.

  • Illman, W. A., Strong field evidence of directional permeability scale effect in fractured rock. J. Hydrol., 2006, 319(1), 227–236.

  • Zhang, G. Q. and Fan, T., A high-stress tri-axial cell with pore pressure for measuring rock properties and simulating hydraulic fracturing. Measurement, 2014, 49, 236–245.


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  • Experimental Study on The Hydraulic Fracture Propagation In Shale

Abstract Views: 252  |  PDF Views: 87

Authors

Shuai Heng
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province - 454000, China
Chunhe Yang
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei - 430071, China
Lei Wang
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei - 430071, China
J. J. K. Daemen
Machay School of Earth Sciences and Engineering, University of Nevada, Reno, NV, United States

Abstract


To realize the control on geometry of fracture network and improve the individual well production of shale gas reservoirs, hydraulic fracturing simulation tests of shale outcrops for horizontal well were carried out. This was based on an established true triaxial hydraulic fracturing simulation test system, to analyse the propagation and formation of a complex fracture network. The results show that the typical severe fluctuation of pump pressure during extension, is an obvious feature of hydraulic fracturing by Stimulated Reservoir Volume (SRV). Due to the large size and abundant natural fractures in shale specimens, the acoustic emission (AE) energy is weak during propagation of hydraulic fractures. However, fracture propagation can still be effectively determined to some extent, although relatively few AE events are detected. Hydraulic fractures from horizontal well initiate approximately along the maximal in situ stress. But the fractures gradually deviate from the orientation when extending. Branching, re-orientation or penetrating bedding planes and then interconnecting with natural fractures or weak beddings are the main mechanisms of the formation of complicated fracture networks.

Keywords


Fracture Propagation, Fracture Network, Hydraulic Fracturing, Shale, Stimulated Reservoir Volume.

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DOI: https://doi.org/10.18520/cs%2Fv115%2Fi3%2F465-475