Effect of Hydraulic Fracture on the Fractured Reservoir Based on the Connection with Natural Fractures

Document Type: paper

Authors

1 Departmentof Petroleum Engineering, Shahid Bahonar University of Kerman, Iran Young Researchers Society

2 Department of Petroleum Engineering, Environmental and Energy Research Center, Shahid Bahonar University of Kerman, Iran

Abstract

Hydraulic fracturing in the fractured reservoirs plays a significant impact on the production rate. In this study, the hydrostatic condition is taken into account, the hydraulic fracturing operation was applied in every direction usinga written distinct element code. In each direction the hydraulic fracture is applied with different lengths and in each level the amount of production is predicted. The impact of interaction of natural fractures and hydraulic fractures on the amount of production is discussed and the number of natural fractures which are intersected by hydraulic fractures is presented. Hydraulic fracturing operation in different directions with different lengths is economically analyzed. In fractured reservoirs the best scenario is that the hydraulic fracture is created in a direction that intersects a group of high permeable natural fractures/parts of the reservoir that are actively participating in flow or the parts with high pore pressures and no connection to the well. The reason isthat connecting the natural fractures which are near the well does not have a significant effect on the production rate. According to the results, creating the hydraulic fractures in a direction with no fractures significantly affects the production rate.

Keywords


[1] Zhang, Z. and Ghassemi, A. (2011). "Simulation of hydraulic fracture propagation near a natural fracture using virtual multidimensional internal bonds." Int. J. for Numerical and Analytical Methods in Geomechanics, 35(4): pp.480-495.

[2] Weng, X., Kresse, O., Cohen, C., Wu, R. and Gu, H. (2011). "Modeling of Hydraulic Fracture Network Propagation in a Naturally Fractured Formation." Paper SPE 140253 presented at SPE hydraulic fracturing technology conference and exhibition. The Woodlands, Texas, USA, 24 26 January.

[3] Fisher, M.K., Wright, C.A., Davidson, B.M., Goodwin, A.K., Fielder, E.O., Bucckler, W.s. and Steinsberger, N.P. (2005). "Integrating Fracture- Mapping Technologies to Improve Stimulations in the Barnett Shale." SPE prod and Fac., pp. 85-93.

[4] Freund, L.B. (1990). "Dynamic fracture mechanics." Cambridge University Press.

[5] Laubach, S. E., Olson, J. E. and Gale, J. (2004). "Are open fractures necessarily aligned with maximum horizontal stress?" Earth & Planetary Science Letters, V. 222 (1), pp.191-195.

[6] Hallam, S.D. and Last, N.C. (1991). "Geometry of hydraulic fractures from modestly deviated wellbores." J. Pet. Technol., Vol. 43, pp. 742-748.

[7] Mack, M.G. and Warpinkski, N.R. (2000). Mechanics of Hydraulic Fracturing.chapter 6 in M.J. Economides, and K.G. Nolte, Reservoir Stimulation.3th.Ed. Wiley Publishers, 750 pp.

[8] Evans, K.F. (2005). "Permeability creation and damage due to massive fluid injections into granite at 3, 5 kmatSoultz: 2. Crit. stress fracture strength." J. Geophys. Res. 110, B04204.

[9] Cornet, F.H., Bérard, T. and Bourouis, S. (2007). "How close to failure is a granite rock mass at a5 km depth?" Int. J. Rock Mech. Min. Sci. 44 (1), pp. 47–66.

[10] Brudy, M., Zoback, M.D., Fuchs, K., Rummel, F. and Baumgrtner, J. (1997). "Estimation of the complete stress tensor to 8 km depth in the KTB scientific drill holes: implications for crustal strength." J. Geophys. Res. 102, pp. 18453–18475.

[11] Zoback, M.D., Barton, C.A., Brudy, M., Castillo, D.A., Finkbeiner, T., Grollimund, B.R., Moos, D.B., Peska, P., Ward, C.D. and Wiprut, D.J. (2003). "Determination of stress orientation and magnitude in deep wells." .Int. J. Rock Mech. Min. Sci. 40, pp. 1049–1076.

[12] Haimson, B. (2007). "Micromechanisms of borehole instability leading to breakouts in rocks." .Int. J. Rock Mech. Min. Sci. vol. 44, pp. 157–173.

[13] Shapiro, S.A., Huenges, E. and Borm, G. (1997). "Estimating the crust permeability from fluid injection-induced seismic emission at the KTB site." Geophys. J. Int. 132, F15–F18.

[14] Baisch, S. and Harjes, H.-P. (2003). "A model for fluid-injection-induced seismicity at the KTB, Germany." Bull. Seismol. Soc. Am. 152 (1), pp. 160–170.

[15] Bohnhoff, M., Baisch, S. and Harjes, H.-P. (2004). "Fault mechanisms of induced seismicity at the super deep German Continental Deep Drilling Program (KTB) borehole and their relation to fault structure and stress field." J. Geophys. Res. 109, B02309.doi:10.1029/200.

[16] Michelet, S. and Toksöz, M.N. (2007). "Fracture mapping in the Soultz-sous-Forêtsgeo thermal field using microearthquake locations." J. Geophys. Res. 112, B07315. doi:10.1029/2006JB004442.

[17] Zoback, M.D. and Harjes, H.-P. (1997). "Injection-induced earthquakes and crustal stress at 9 km depth at the KTB deep drilling site." Germany. J. Geophys. Res. 102, pp. 18477–18491.

[18] Legarth, B., Tischner, T. and Huenges, E. (2003). "Stimulation experiments in sedimentary, low-enthalpy reservoirs for geothermal power generation." Germany. Geothermics32 (4–6), pp. 487–495.

[19] Legarth, B., Huenges, E. and Zimmermann, G. (2005). “Hydraulic fracturing in a sedimentary geothermal reservoir: Results and implications." .Int. J. Rock Mech. Min. Sci. 42, 1028–1041.