Numerical simulation of fault activity owing to hydraulic fracturing
Hu Jun1,2, Cao Jun-Xing2, He Xiao-Yan2, Wang Quan-Feng1, and Xu Bin1
1. Chengdu University of Technology, Geomathematics Key Laboratory of Sichuan Province, Chengdu 610059, China.
2. Chengdu University of Technology, State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu 610059, China.
Abstract：
We built a three-dimensional model to simulate the disturbance of the stress field near the reverse fault in Zhaziao, Leyi Township owing to hydraulic fracturing. The pore pressure, and shear and normal stresses during fracturing are analyzed in detail. Input rock mechanics parameters are taken from laboratory test data of shale samples from the study area. The simulation results suggest that after 16 hours of fluid injection, the pore-pressure variation can activate the reverse fault, i.e., we observe reverse slip, and the shear stress and displacement on the fault plane increase with time. The biggest stress–strain change occurs after one hour of fluid injection and the yield point appears about 0.5 h after injection. To observe the stress evolution in each section, the normal displacement on the boundary is constrained and the fault plane is set as nonpermeable. Thus, the sliding is limited and the shear displacement is only in the scale of millimeters, and the calculated magnitude of the induced earthquakes is between Mw-3.5 and Mw-0.2. The simulation results suggest that fluid water injection results in inhomogeneous fracturing. The main ruptured areas are around the injection positions, whereas the extent of rupturing and cracks in other areas are relatively small. Nevertheless, nonnegligible fault activation is recorded. Sensitivity analysis of the key parameters suggests that the pore pressure is most sensitive to the maximum unbalanced force and the internal friction angle strongly affects the fault slip. Finally, the comparison between the effective normal stress and the maximum and minimum principal stresses on the fault plane explains the fault instability, i.e., the Mohr circle moves towards the left with decreasing radius reduces and intersects the critical slip envelope, and causes the fault to slip.
. Numerical simulation of fault activity owing to hydraulic fracturing[J]. APPLIED GEOPHYSICS, 0, (): 367-381.
[1]
Kanamori, H., and Brodsky, E. E., 2004, The physics of earthquakes: Physics Today, 54(6), 1429−1496. Doi:10.1088/0034-4885/67/8/R03.
[2]
Atkinson, C., Smelser, R. E., and Sanchez, J., 1982, Combined mode fracture via the cracked Brazilian disk test: International Journal of Fracture, 18(4), 279-291.
[3]
Lei, X. L., Huang, D. J., Su, J. R., Jiang, G. M., Wang, X. L., Wang, H., Guo, X., and Fu, H., 2017, Fault reactivation and earthquakes with magnitudes of up to Mw4.7 induced by shale-gas hydraulic fracturing in Sichuan Basin, China: Scientific reports, 7, 7971. Doi:10.1038/s41598-017-08557-y.
[4]
Li, K., Zhang, H., Ran, C., and Shao, M. J., 2016, Productivity Model of Shale Gas Well with Consideration of Stress Sensitivity: Taking Longmaxi Formation Shale Gas Reservoir in Southeastern Sichuan Basin as an Example: Journal of Xi'an Shiyou University (Natural Science Edition), 31(3), 57−61. Doi: 10.3969/ j.issn.1673-064X.2016.03.009
[5]
Atkinson, G. M., Eaton, D. W., Ghofrani, H., Walker, D., Cheadle, B., Schultz, R., Shcherbakov, R., Tiampo, K., Gu, J., Harrington, R. M., Liu, Y. J., van der Baan, M., and Kao, H., 2016, Hydraulic Fracturing and Seismicity in the Western Canada Sedimentary Basin: Seismological Research Letter, 87(3), 631−647. Doi:10.1785/0220150263.
[6]
Li, Q. H., Chen, M., Jin, Y., Hou, B., and Zhang, J. Z., 2012, Rock mechanical properties and brittleness evaluation of shale gas reservoir:. Petroleum Drilling Techniques, 40(4), 18−22. Doi:10.3969/ j.issn.1001-0890.2012.04.004.
[7]
Bao, X. W., and Eaton, D. W., 2016, Fault activation by hydraulic fracturing in western Canada: Science, 354(6318), 1406−1409. Doi:10.1126/science.aag,2583.
[8]
Li, Z. L., Zhang, H. C., Ren, Q. W., and Wang, Y. H., 2005, Analysis of hydraulic fracturing and calculation of critical internal water pressure of rock fracture: Rock and Soil Mechanics, 26(8), 1216−1220.
[9]
Chen, J. G., Deng, J. G., Yuan, J. L., Yan, W., Yu, B. H., and Tan, Q., 2015, Determination of fracture toughness of modes I and II of shale formation: Chinese Journal of Rock Mechanics and Engineering, 34(6), 1101−105. Doi:10.13722/j.cnki.jrme.2014.1187.
[10]
Liu, S. G., Ma, W. X., Luba, J., Huang, W. M., Zeng, X. L., and Zhang, C. J., 2011, Characteristics of the shale gas reservoir rocks in the Lower Silurian Longmaxi Formation, East Sichuan basin, China: Acta Petrologica Sinica, 27(8), 2239−2252. Doi: 1000-0569/2011/027(08)-2239-52.
[11]
Clarke, H., Eisner, L., Styles, P., and Turner, P., 2014. Felt seismicity associated with shale gas hydraulic fracturing: The first documented example in Europe. Geophysical Research Letters, 2015, 41(23), 8308−8314. Doi:10.1002/2014GL062047.
[12]
Lund Snee, J. -E., and Zoback, M. D., 2016, State of stress in Texas: Implications for induced seismicity: Geophysical Research Letters, 43, 10208−10214. Doi:10.1002/2016GL070974.
[13]
Crampin, S., Peacock, S., Gao, Y., and Chastin, S., 2004. The scatter of time-delays in shear-wave splitting above small earthquakes: Geophys. J. Int., 156, 39−44.
[14]
McGarr, A., 1991, On a possible connection between three major earthquakes in California and oil production. BSSA, 81(3), 948−970.
[15]
Crampin, S., and Gao, Y., 2013, The new geophysics: Terra Nova, 25(3), 173−180.
[16]
McGarr, A., 2014, Maximum magnitude earthquakes induced by fluid injection. Journal of Geophysical Research: Solid Earth. 119(2), 1008-1019. Doi:10.1002/2013JB010597.
[17]
Plenefisch, T., and Bonjer, K. P., 1997, The stress field in the Rhine Graben area inferred from earthquake focal mechanisms and estimation of frictional parameters: Tectonophysics, 275, 71−97.
[18]
Deng, K., Liu, Y. J., and Harrington, R. M., 2016, Poroelastic stress triggering of the December 2013 Crooked Lake, Alberta, induced seismicity sequence: Geophysical Research Letters, 43, 8482-8491. Doi:10.1002/2016GL070421.
[19]
Ding, S. D., and Sun, L. M., 1997, Fracture mechanics: China Machine Press, Beijing.
[20]
Schultz, R., Stern, V., Novakovic, M., Atkinson, G., and Gu, Y. J., 2015, Hydraulic fracturing and the Crooked Lake Sequences: Insights gleaned from regional seismic networks: Geophys. Res. Lett. 42, 2750−2758. Doi:10.1002/2015GL063455.
[21]
Skoumal, R., Brudzinski, M. R., and Currie, B. S., 2015. Earthquakes induced by hydraulic fracturing in Poland Township, Ohio: Bull. Seismol. Soc. Am. 105(1), 189-197. Doi:10.1785/0120140168.
[22]
Song, C. P., Lu, Y. Y., Jia, Y. Z., and Xia, B. W., 2014, Effect of Coal-Rock interface on hydraulic fracturing propagation: Journal of Northeastern University (Natural Science), 35(9), 1340-1345.
Wang, J. L., Liu, G. J., Wang, W. Z., Zhang, S. J., and Yuan, L. L., 2013, Characteristics of pore-fissure and permeability of shales in the LongmaxiFormation in southeastern Sichuan Basin: Journal of China Coal Society, 38(5), 772−777. Doi: 0253-9993(2013)05-0772-06.
[25]
Friberg, P. A., Besana-Ostman, G. M., and Dricker, L., 2014, Characterization of an earthquake sequence triggered by hydraulic fracturing in Harrison County, Ohio: Seismol. Res. Lett., 85(6), 1295−1307. Doi: 10.1785/0220140127.
[26]
Wang, Q., Wang, P., Xiang, D. G., and Feng, Y. S., 2012, Anisotropic property of mechanical parameters of shales: Natural Gas Industry, 32(12), 62−65. Doi:10.3787/j.issn.1000-0976.2012.12.013.
[27]
Galis, M., Ampuero, J. P., Mai, P. M., and Cappa, F., 2017, Induced seismicity provides insight into why earthquake ruptures stop: Science Advances, 3(12), eaap7528. Doi:10.1126/sciadv.aap7528.
[28]
Holland, A. A., 2013, Earthquakes triggered by hydraulic fracturing in south-central Oklahoma: Bulletin of the Seismological Society of America, 103(3), 1784-1792. Doi: 10.1785/0120120109.
[29]
Itasca Consulting Group Inc., 2015, FLAC3D-fast Lagrangian analysis of continua in 3 dimensions: User’s Manual, Minneapolis: Itasca.
[30]
Irwin, G. R., 1947, Fracture dynamics: Fracturing of Metals Seminar, American Society for Metals, 147−166.
[31]
Jaeger, J. C., and Cook, N. G. W., 2007, Fundamentals of Rock Mechanics (4th Edition): Chapman and Hall, London.
[32]
Kanamori, H., and Anderson, D. L., 1975, Theoretical basis of some empirical relations in seismology: Bull. Seismol.Soc.Am, 65(5), 1073-1095.
[33]
Kanamori, H., and Brodsky, E. E., 2004, The physics of earthquakes: Physics Today, 54(6), 1429−1496. Doi:10.1088/0034-4885/67/8/R03.
[34]
Wang, Y. M., Dong, D. Z., Li, J. Z., Wang, S. J., Li, X. J., Wang, L., Cheng, K. M., and Huang, J. L., 2012, Reservior characteristics of shale gas in Longmaxi Formation of the Lower Silurian, southern Sichuan: Acta Petrolei Sinica, 33(4), 551−561. Doi: 0253-2697(2012)04-0551-11.
[35]
Wei, X. C., Li, Q., Li, X. Y., and Niu, Z. Y., 2016, Modeling the hydromechanical responses of sandwich structurefaults during underground fluid injection: Environment Earth Science (2016), 75, 1155. Doi:10. 1007/s12665-016-5975-9.
[36]
Lei, X. L., Huang, D. J., Su, J. R., Jiang, G. M., Wang, X. L., Wang, H., Guo, X., and Fu, H., 2017, Fault reactivation and earthquakes with magnitudes of up to Mw4.7 induced by shale-gas hydraulic fracturing in Sichuan Basin, China: Scientific reports, 7, 7971. Doi:10.1038/s41598-017-08557-y.
[37]
Zoback, M. L., 1992, Stress field constrains on intraplate seismicity in Eastern North America: Journal of Geophysics Research, 97(B8), 11761−11782.
0, Vol. 
