汶川地震断裂带科学钻一号孔ASR法地应力测量
摘要
大地震后发震断裂附近的应力状态是认识和理解地震机理的重要参数。5.12汶川地震后,我国开展了基于地震机理研究的汶川地震断裂带科学钻探项目(Wenchuan Earthquake Fault Scientific Drilling Project,简称WFSD),为研究震后龙门山断裂带附近深部应力状态提供了条件。本文主要介绍适合深部应力测量的非弹性应变恢复法(Anelastic strain recovery method,简称ASR法)的测试设备和流程,并利用ASR法对WFSD-1号钻孔岩心进行了原地应力测量,取得了该钻孔424～1173 m深度范围内7个岩心样品的非弹性应变恢复实测数据,并根据成像测井对岩心进行了定向,确定了原地应力方向,估算了原地应力的大小。WFSD-1钻孔最大主应力的方位为NW69°～NW35°,主应力的大小随深度的增加而增大。
The in-situ stress state of seismogenic fault after a strong earthquake is one of the important parameters for understanding the mechanism of the earthquake.The Wenchuan earthquake Fault Scientific Drilling project(WFSD) is a rapid response to the 2008 Ms 8.0 Wenchuan earthquake,which provided the test rock core for recognizing the stress state of the depth of Longmenshan fault on the eastern margin of the Tibetan Plateau.This paper focuses on the measuring instruments and processes of the anelastic strain recovery method(ASR) for the deep in-situ stress measurement.The anelastic recovery strains of seven different deep cores are in the range of 424-1173m in WFSD-1.The direction and magnitude of principal stress were determined and estimated,respectively.The dominant azimuths of maximum principal stress are between NW69° and NW35°,and the magnitude of principal stress increases with the increasing depth.
The in-situ stress state of seismogenic fault after a strong earthquake is one of the important parameters for understanding the mechanism of the earthquake.The Wenchuan earthquake Fault Scientific Drilling project(WFSD) is a rapid response to the 2008 Ms 8.0 Wenchuan earthquake,which provided the test rock core for recognizing the stress state of the depth of Longmenshan fault on the eastern margin of the Tibetan Plateau.This paper focuses on the measuring instruments and processes of the anelastic strain recovery method(ASR) for the deep in-situ stress measurement.The anelastic recovery strains of seven different deep cores are in the range of 424-1173m in WFSD-1.The direction and magnitude of principal stress were determined and estimated,respectively.The dominant azimuths of maximum principal stress are between NW69° and NW35°,and the magnitude of principal stress increases with the increasing depth.
引文
[1]Boh nhoff M,Baisch S,HarjesH P.Fault mechanisms of inducedseismicity at the superdeep German Continental Deep DrillingProgram(KTB)borehole and their relation to fault structure andstress field[J].J Geophy.Res.,2004,109,B02309,doi:10.1029/2003JB002528.
[2]Hickman S,Zoback M.Stress orientations and magnitudes in theSAFOD pilot hole[J].Geophy.Res.Lett.,2004,31,L15S12,doi:10.1029/2004GL020043.
[3]Wu H Y,Ma K F,Zoback M,et al.Stress orientations of TaiwanChelungpu-Fault Drilling Project(TCDP)hole-A as observedfrom geophysical logs[J].Geophy.Res.Lett.,2007,34,L01303,doi:10.1029/2006GL028050.
[4]YamashitaF,Fukuyama E,Omura K.Estimation of fault strength:reconstruction of stress before the 1995 Kobe earthquake[J].Science,2004,306:261-263.
[5]Lin W,et al.Present-day principal horizontal stress orientations inthe Kumano forearc basin of the southwest Japan subduction zonedetermined from IODP NanTroSEIZE drilling Site C0009[J],Geophys.Res.Lett.,2010,37,L13303,doi:10.1029/2010GL043158.
[6]Li H,Wang H,Xu Z,et al.Characteristics of the fault-related rocks,fault zones and the principal slip zone in the Wenchuan EarthquakeFault Scientific Drilling Project Hole-1(WFSD-1)[J].Tectonophysics,2012,http://dx.doi.org/10.1016/j.tecto.2012.08.021.
[7]林为人.基于岩心非弹性应变恢复量测定的深孔三维地应力测试方法[J].岩石力学与工程学报,2008,27(12):2387-2394.
[8]王连捷,孙东生,林为人,等.地应力测量的非弹性应变恢复法及应用实例[J].地球物理学报,2012,55(5):1674-1681.Wang Lianjie,Sun Dongsheng,Lin Weiren,et al.Anelastic strain recovery method to determine in-situ stress and application example[J].Chinese Journal of Geophysics,2012,55(5):1674-1681(in Chinese with English abstract).
[9]Zang A,Stephansson O.Stress field of the earth’s crust.Springer,London.2010,115-193.
[10]王连捷,李朋武,崔军文,等.中国大陆科学钻探主孔声发射法现今地应力状态的确定[J].中国地质,2005,32(2):259-264.Wang Lianjie,Li Pengwu,Cui Junwen,et al.Determination of the present crustal stress state by using acoustic emission in the main borehole of the Chinese Continental Scientific Drilling[J].Geology in China,2005,32(2):259-264(in Chinese with English abstract).
[11]孙东生,王连捷,赵卫华,等.地应力测量在煤与瓦斯突出灾害研究中的应用[J].中国地质,2010,37(1):223-228 Sun Dongsheng,Wang Lianjie,Zhao Weihua,et al.The application of in-situ stress measurement to the study of coal and gas outburst in coal mines[J].Geology in China,2010,37(1):223-228(in Chinese with English abstract).
[12]Voight B.Determination of the virgin state of stress in the vicinity of a borehole from measurements of a partial anelastic strain tensorin drill cores[J].Felsmechanik und Ingenieurgeologie,1968,6:201-215.
[13]Engelder T.The time-dependent strain relaxation of Algerie granite[J].Int.J.Rock Mech Min SciGeomechAbstr,1984,21(2):63-73.
[14]Warpinski NR,Teufel LW.In-situ stresses in low permeability,nonmarine rocks[J].J.Pet.Tech.,1989,41:405-414.
[15]Perreau PJ,Heugas O,Santarelli F J.Tests of ASR,DSCA,and core discing analyses to evaluate in-situ stresses.SPE paper17960,SPE Middle East Oil Technical Conference and Exhibition Manama,Bahrain,1989,325-336
[16]Lin W.et al.,Current Stress State and Principal Stress Rotations in the Vicinity of the Chelungpu Fault Induced by the1999Chi-Chi,Taiwan,Earthquake[J].Geophys.Res.Lett.,2007,34,L16307,doi:10.1029/2007GL030515.
[17]Lin W,Kwasniewski M,Imamura T,et al.Determination of three-dimensional in-situ stresses from anelastic strain recovery measurement of cores at great depth[J].Tectonophysics,2006,426(1/2):221-238.
[18]Byrne T B,W Lin A.Tsutsumi,et al.Anelastic strain recovery reveals extension across SW Japan subduction zone[J].Geophys.Res.Lett.,2009,36,L23310,doi:10.1029/2009GL040749.
[19]J C耶格,N G W库克(著).中国科学院工程力学研究所(译).岩石力学基础[M].北京:地震出版社,1981:382-397.Jaeger J C,Cook N G W.Fundamentals of rock mechanics[M].Institute of Engineering Mechanics,Chinese Academy of Sciences(Translated).Beijing:Seismological Press,1981:382-397(in Chinese with English abstract).
[2]Hickman S,Zoback M.Stress orientations and magnitudes in theSAFOD pilot hole[J].Geophy.Res.Lett.,2004,31,L15S12,doi:10.1029/2004GL020043.
[3]Wu H Y,Ma K F,Zoback M,et al.Stress orientations of TaiwanChelungpu-Fault Drilling Project(TCDP)hole-A as observedfrom geophysical logs[J].Geophy.Res.Lett.,2007,34,L01303,doi:10.1029/2006GL028050.
[4]YamashitaF,Fukuyama E,Omura K.Estimation of fault strength:reconstruction of stress before the 1995 Kobe earthquake[J].Science,2004,306:261-263.
[5]Lin W,et al.Present-day principal horizontal stress orientations inthe Kumano forearc basin of the southwest Japan subduction zonedetermined from IODP NanTroSEIZE drilling Site C0009[J],Geophys.Res.Lett.,2010,37,L13303,doi:10.1029/2010GL043158.
[6]Li H,Wang H,Xu Z,et al.Characteristics of the fault-related rocks,fault zones and the principal slip zone in the Wenchuan EarthquakeFault Scientific Drilling Project Hole-1(WFSD-1)[J].Tectonophysics,2012,http://dx.doi.org/10.1016/j.tecto.2012.08.021.
[7]林为人.基于岩心非弹性应变恢复量测定的深孔三维地应力测试方法[J].岩石力学与工程学报,2008,27(12):2387-2394.
[8]王连捷,孙东生,林为人,等.地应力测量的非弹性应变恢复法及应用实例[J].地球物理学报,2012,55(5):1674-1681.Wang Lianjie,Sun Dongsheng,Lin Weiren,et al.Anelastic strain recovery method to determine in-situ stress and application example[J].Chinese Journal of Geophysics,2012,55(5):1674-1681(in Chinese with English abstract).
[9]Zang A,Stephansson O.Stress field of the earth’s crust.Springer,London.2010,115-193.
[10]王连捷,李朋武,崔军文,等.中国大陆科学钻探主孔声发射法现今地应力状态的确定[J].中国地质,2005,32(2):259-264.Wang Lianjie,Li Pengwu,Cui Junwen,et al.Determination of the present crustal stress state by using acoustic emission in the main borehole of the Chinese Continental Scientific Drilling[J].Geology in China,2005,32(2):259-264(in Chinese with English abstract).
[11]孙东生,王连捷,赵卫华,等.地应力测量在煤与瓦斯突出灾害研究中的应用[J].中国地质,2010,37(1):223-228 Sun Dongsheng,Wang Lianjie,Zhao Weihua,et al.The application of in-situ stress measurement to the study of coal and gas outburst in coal mines[J].Geology in China,2010,37(1):223-228(in Chinese with English abstract).
[12]Voight B.Determination of the virgin state of stress in the vicinity of a borehole from measurements of a partial anelastic strain tensorin drill cores[J].Felsmechanik und Ingenieurgeologie,1968,6:201-215.
[13]Engelder T.The time-dependent strain relaxation of Algerie granite[J].Int.J.Rock Mech Min SciGeomechAbstr,1984,21(2):63-73.
[14]Warpinski NR,Teufel LW.In-situ stresses in low permeability,nonmarine rocks[J].J.Pet.Tech.,1989,41:405-414.
[15]Perreau PJ,Heugas O,Santarelli F J.Tests of ASR,DSCA,and core discing analyses to evaluate in-situ stresses.SPE paper17960,SPE Middle East Oil Technical Conference and Exhibition Manama,Bahrain,1989,325-336
[16]Lin W.et al.,Current Stress State and Principal Stress Rotations in the Vicinity of the Chelungpu Fault Induced by the1999Chi-Chi,Taiwan,Earthquake[J].Geophys.Res.Lett.,2007,34,L16307,doi:10.1029/2007GL030515.
[17]Lin W,Kwasniewski M,Imamura T,et al.Determination of three-dimensional in-situ stresses from anelastic strain recovery measurement of cores at great depth[J].Tectonophysics,2006,426(1/2):221-238.
[18]Byrne T B,W Lin A.Tsutsumi,et al.Anelastic strain recovery reveals extension across SW Japan subduction zone[J].Geophys.Res.Lett.,2009,36,L23310,doi:10.1029/2009GL040749.
[19]J C耶格,N G W库克(著).中国科学院工程力学研究所(译).岩石力学基础[M].北京:地震出版社,1981:382-397.Jaeger J C,Cook N G W.Fundamentals of rock mechanics[M].Institute of Engineering Mechanics,Chinese Academy of Sciences(Translated).Beijing:Seismological Press,1981:382-397(in Chinese with English abstract).
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心