Modeling Hydraulic Failure Process Using Elasto-Plastic Cellular Automaton

Abstract

Abstract: A self-developed numerical tool, i.e. an elasto-plastic cellular automaton (EPCA) was used to simulate the hydraulic fracturing process of rocks. The modeling method of hydraulic fracturing process of heterogeneous rocks with cellular automaton was developed. With the increase of fluid load, fluid will go into the new cracks. The new fluid seepage boundaries will be formed and the tensile stress induced by fluid will be applied on the crack boundaries. In this process, the mechanical properties and boundary conditions will be updated dynamically. The cellular automaton, which is based on the localization theory, makes this operation more conveniently. With this method, the failure process of wellbore rock specimen under hydraulic pressure was simulated, by considering different heterogeneity and different inner radius of the wellbore. It is concluded that, in hydraulic fracturing process, the critical fluid pressure, crack propagation and final failure patterns etc. are greatly influenced by the heterogeneity of the rock, the boundary geometry etc.

Key words: coupled hydro-mechanics, elastoplastic cellular automaton (EPCA), hydro-fracturing, rock failure process, heterogeneity

CLC Number:

TU454

PAN Peng-Zhi-1, FENG Xia-Ting-1, WU Hong-Xiao-2, SUN Feng-1, ZHOU Hui-1. Modeling Hydraulic Failure Process Using Elasto-Plastic Cellular Automaton[J]. Journal of Shanghai Jiaotong University, 2011, 45(05): 722-727.

References

［1］Tsang C F. Coupled processes associated with nuclear waste repositories［M］. New York: Academic Press, 1987.

［2］Tsang C F. Coupled thermomechanical and hydrochemical processes in tock fractures［J］. Review of Geophysics,1991, 29(5): 537548.

［3］Jing L R, Feng X T. Numerical modeling for coupled thermohydromechanical and chemical processes (THMC) of geological mediainternational and Chinese experiences［J］. Chinese Journal of Rock Mechanics and Engineering，2003，22(10)：17041715.

［4］Jing L, Stephansson O, Tsang C F, et al. DECOVALEX mathematical models of coupled THM processes for nuclear waste repositories［M］. Stockholm, Sweden: Executive Summary for PhaseⅠ、Ⅱ and Ⅲ. SKI report 96:58. Swedish Nuclear Power Inspectorate, 1996.

［5］Jing L R, Stephansson O, Tsang C F, et al. DECOVALEX Ⅱ project, executive summary［M］. Stockholm, Sweden: SKI Report 99:24. Swedish Nuclear Power Inspectorate, 1999.

［6］Stephansson O, Hudson J A, Jing L R. International conference on coupled THMC processes in geosystems: Fundamentals, Modelling, Experiments and Applications［M］. Stockholm, Sweden: Elsevier, 2003.

［7］Huttert M K, Willis D G. Mechanic of hydraulic fracturing［J］. Transactions of American Institute of Mining Engineers, 1957, 210: 153168.

［8］Haimson B. Hydraulic fracturing in porous and nonporous rock and its potential for determining insite stress at great depth［D］. Minnesota: University of Minnesota, 1968.

［9］Blair S C, Thorpe R K, Shaffer F E. Laboratory observations of the effect of geologic discontinuities on hydorfracture propagation［C］//Rock Mechanics as a Guide for Efficient Utilization of Natural Resources. Rotterdam: Balkema, 1989.

［10］Kim C M, Abass H H. Hydraulic fracture initiation from horizontal wellbores: Laboratory experiments［C］// Rock Mechanics as a Multidisciplinary Science, Proceedings of the 32nd U.S. Symposium. Rotterdam: Balkema, 1991: 231240.

［11］De Pater C J, Weyers L, Savic M, et al. Experimental study of nonlinear effects in hydraulic fracture propagation［J］. SPE, 1993:25893.

［12］Sousa J L. Threedimensional simulation of nearwellbore phenomena related to hydraulic fracturing from a perforated wellbore［D］. New York: Cornell University, 1992.

［13］王建军. 应用水压致裂法测量三维的应力的几个问题［J］. 岩石力学与工程学报，2000，19(2): 229233.

WANG Jianjun. Several problems in application of hydraulic fracturing method to insitu 3D stress measurement［J］. Chinese Journal of Rock Mechanics and Engineering, 2000，19(2): 229233.

［14］刘允芳. 水压致裂法三维地应力测量［J］. 岩石力学与工程学报, 1991，10(3): 246256.

LIU Yunfang. Insitu 3D stress measurements by hydraulic fracturing technique［J］. Chinese Journal of Rock Mechanics and Engineering, 1991，10(3): 246256.

［15］张延新，宋常胜，蔡美峰，等. 深孔水压致裂地应力测量及应力场反演分析［J］. 岩石力学与工程学报，2010，29(4): 778786.

ZHANG Yanxin, SONG Changsheng, CAI Meifeng, et al. Geostress measurements by hydraulic fracturing method at great depth of boreholes and numerical modeling predictions of stress field［J］. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(4): 778786.

［16］詹美礼，岑建. 岩体水力劈裂机制圆筒模型试验及解析理论研究［J］. 岩石力学与工程学报, 2007， 26(6): 11731182.

ZHAN Meili, CEN Jian. Experimental and analytical study on hydraulic fracturing of cylinder sample［J］. Chinese Journal of Rock Mechanics and Engineering, 2007， 26(6): 11731182.

［17］冯晓莹，徐泽平. 心墙水力劈裂机理的离心模型试验研究［J］. 水利学报，2009，40(10): 12591263.

FENG Xiaoying, XU Zeping. Centrifugal model study on mechanism of hydraulic fracturing of clay corewall in rockfill dams［J］. Shuili Xuebao，2009，40(10): 12591263.

［18］陈勉，庞飞，金衍. 大尺寸真三轴水力压裂模拟与分析［J］. 岩石力学与工程学报, 2000, 19(增刊)：868872.

CHEN Mian, PANG Fei, JIN Yan. Experiments and analysis on hydraulic fracturing by a largesize triaxial simulator［J］. Chinese Journal of Rock Mechanics and Engineering，2000，19(Sup.)：868872.

［19］唐红侠，周志芳，王文远. 水劈裂过程中岩体渗透性规律及机理分析［J］. 岩土力学, 2004, 25(8): 13201322.

TANG Hongxia, ZHOU Zhifang, WANG Wenyuan. Permeability of rock and mechanism analysis during hydraulic fracturing［J］. Rock and Soil Mechanics，2004，25(8): 13201322.

［20］李连崇，杨天鸿，唐春安，等. 岩石水压致裂过程的耦合分析［J］. 岩石力学与工程学报，2003，22(7)：10601066.

LI Lianchong, YANG Tianhong, TANG Chunan, et al. Chinese Journal of Rock Mechanics and Engineering，2003，22(7)：10601066.

［21］郭保华. 单孔岩样水压致裂的数值分析［J］. 岩土力学，2010，31(6): 19651970.

GUO Baohua. Numerical analysis of hydraulic fracturing on singleholed rock specimens［J］. Rock and Soil Mechanics，2010，31(6): 19651970.

［22］姜文忠，张春梅，姜勇，等. 水压致裂作用对岩石渗透率影响数值模拟［J］. 辽宁工程技术大学学报:自然科学版，2009，28(5): 693697.

JIANG Wenzhong, ZHANG Chunmei, JIANG Yong, et al. Numerical simulation of rock permeability enhanced by hydraulic fracturing［J］. Journal of Liaoning Technical University:Nature Science,2009，28(5): 693697.

［23］Feng X T, Pan P Z, Zhou H. Simulation of rock microfracturing process under uniaxial compression using elastoplastic cellular automata［J］. Int J Rock Mech and Min Sci，2006，43(7): 10911108.

［24］Pan P Z, Feng X T, Zhou H. Simulation of rock fracturing in an HM coupling environment using a cellular automaton［C］//The 2nd International Conference on Coupled THMC Processes in Geosystems. Fundamentals, Modeling, Experiments and Applications. Nanjing: Science Press, 2006: 503508.

［25］王国庆. 岩体水力劈裂试验及裂纹扩展的无单元法计算［D］. 南京：河海大学水利水电学院, 2004.

[1]	CHEN Feier (陈飞儿), ZHAO Qiyuan (赵祺源), CAO Mingming (曹明明), CHEN Jiayi (陈嘉屹), FU Guiyuan (傅桂元). Adaptive Agent-Based Modeling Framework for Collective Decision-Making in Crowd Building Evacuation [J]. J Shanghai Jiaotong Univ Sci, 2021, 26(4): 522-533.
[2]	YANG Xing1 (杨星), FAN Chun1* (范纯), LI Gang2* (李刚). Informed Trading, Heterogeneity Investment, Liquidity Shocks and the Valuation of Credit Default Swaps [J]. Journal of shanghai Jiaotong University (Science), 2016, 21(1): 69-80.
[3]	Kai-yong HUANG, Xiang-lian ZHOU, Jian-hua WANG. Numerical Simulation of Drawdown and Land Deformation in Pumping-Recovery Tests Performed on a Circular Excavation [J]. Journal of Shanghai Jiao Tong University(Science), 2015, 20(6): 690-695.
[4]	KE Chang-Ren-1, 2 , JIANG Jun-Ling-2, GE Xiu-Run-1, 3 . Numerical Simulation of Heterogeneous Rock Dynamic Fracture Based on Virtual Internal Bond Model [J]. Journal of Shanghai Jiaotong University, 2012, 46(01): 142-145.