含黄铁矿泥质砂岩电阻率频散规律实验研究与校正方法（英文）
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摘要
含黄铁矿泥质岩石的频散特性使得地层的电阻率测井响应值在高频电阻率测井中会出现失真现象,导致储层的饱和度计算存在较大的难度。为了更好的消除岩石中黄铁矿和泥质的电阻率频散影响,同时弥补天然岩心中各种物质成分、含量,以及分布形式等因素无法人工控制的不足,本文设计并在高温高压下制作了12块含分散状黄铁矿颗粒和粘土颗粒的人造固结岩样,分析岩样在多种电流频率条件下,不同地层水矿化度以及饱和度的岩电实验数据,得出频率对含黄铁矿泥质砂岩导电规律的影响:分散状黄铁矿和粘土颗粒都具有频散特性;随着电流频率的增大,岩样复电阻率实部减小。基于有效介质对称导电理论,结合实验研究成果,考虑黄铁矿含量和泥质含量变化对岩石频散规律的影响,建立了黄铁矿泥质砂岩有效介质复电阻率实部频散模型。理论模拟表明当电流频率、黄铁矿及分散泥质含量变化时,模型预测的黄铁矿泥质砂岩频散规律与实验规律相一致。利用岩电实验数据,验证了该模型可以准确地描述含黄铁矿泥质砂岩储层的频散特征。通过选取多种电测井中应用的电流频率,建立了黄铁矿电导率为0.062 S/m,泥质电导率为0.031 S/m的电阻率频率影响校正图版,给出了运用该图版进行高频电阻率测井响应校正的具体方法,为获取地层的真实电阻率值提供了保障。
In pyrite-bearing shaly sandstones, the distortion in the resistivity logging response of formations in high-frequency resistivity logging because of dispersion hinders the calculation of reservoir saturation. To eliminate the effect of resistivity dispersion of pyrite and shale, and to avoid factors, such as mineral composition, content, and distribution in natural cores, we synthesized twelve samples with dispersed pyrite and shale grains at high temperature and pressure(60 MPa and 120℃). We performed experiments at different water salinities and oil saturations, and different frequency to assess the effect of frequency on the conductivity of pyrite-bearing shaly sandstones. Both the dispersed pyrite and shale grains show dispersion, and the real part of the complex resistivity decreases with increasing frequency. Based on symmetrical effective medium conductivity theory and the experimental data, the effective medium dispersion model for the real part of the complex resistivity for pyrite-bearing shaly sandstones is established considering the effect of pyrite and shale content on resistivity dispersion. Simulations suggest that the predicted resistivity dispersion by the model in pyrite-bearing shaly sandstones for variable frequency, and pyrite and shale content agrees with the experimental results. The proposed model can successfully predict the dispersion of pyrite-bearing shaly sandstones. Finally, the resistivity dispersion correction plot for the conductivity of pyrite and shale grains of 0.062 S/m and 0.031 S/m, respectively, is established based on the frequency applied to various electric logs, and the correction method for the high-frequency resistivity log response is given to obtain the real formation resistivity.
In pyrite-bearing shaly sandstones, the distortion in the resistivity logging response of formations in high-frequency resistivity logging because of dispersion hinders the calculation of reservoir saturation. To eliminate the effect of resistivity dispersion of pyrite and shale, and to avoid factors, such as mineral composition, content, and distribution in natural cores, we synthesized twelve samples with dispersed pyrite and shale grains at high temperature and pressure(60 MPa and 120℃). We performed experiments at different water salinities and oil saturations, and different frequency to assess the effect of frequency on the conductivity of pyrite-bearing shaly sandstones. Both the dispersed pyrite and shale grains show dispersion, and the real part of the complex resistivity decreases with increasing frequency. Based on symmetrical effective medium conductivity theory and the experimental data, the effective medium dispersion model for the real part of the complex resistivity for pyrite-bearing shaly sandstones is established considering the effect of pyrite and shale content on resistivity dispersion. Simulations suggest that the predicted resistivity dispersion by the model in pyrite-bearing shaly sandstones for variable frequency, and pyrite and shale content agrees with the experimental results. The proposed model can successfully predict the dispersion of pyrite-bearing shaly sandstones. Finally, the resistivity dispersion correction plot for the conductivity of pyrite and shale grains of 0.062 S/m and 0.031 S/m, respectively, is established based on the frequency applied to various electric logs, and the correction method for the high-frequency resistivity log response is given to obtain the real formation resistivity.
引文
Alexandre,N.B.,2013,Complex resistivity decomposition of the Dias’s model in partition fractions applied to electrolyte salinity,clay content and hydraulic permeability determination:13th International Congress of the Brazilian Geophysical Society,Brazil Society of Exploration Geophysics,Rio de Janeiro,Brazil,1-10.
Al-Mjeni,R.,Günzel,F.,Jing,X.D.,et al.,2002,The influence of clay fraction on the complex impedance of shaly sands:Society of Core Analysts Conference,September,SCA 2002-29,1-12.
Clavier,C.,Heim,A.,and Scala,C.,1976,Effect of pyrite on resistivity and other logging measurements:17th SPWLA Annual Logging Symposium,Paper HH.
Clennell,M.B.,Josh,M.,Esteban,L.,et al.,2010,The influence of pyrite on rock electrical properties a case study from NW Australian gas reservoirs:51th SPWLA Annual Logging Symposium Australia,Paper UUU.
De Kuijper,A.,Sandor,R.K.J.,Hofman,J.P.,et al.,1996,Electrical conductivities in oil-bearing shaly sand accurately described with the SATORI saturation model:The Log Analyst,37(5),22-31.
Fan,Y.R.,Lu,J.M.,Wang,G.H.,et al.,1994,Experimental study on the dispersion of rock resistivity:Journal of the University of Petroleum,18(1),17-23.
Garrouch,A.A.,and Sharma,M.M.,1994,The influence of clay content,salinity,stress and wettability on the dielectric properties of brine-saturated rocks 10Hz to10MHz:Geophysics,59(6),909-917.
Garrouch,A.A.,and Sharma M.M.,1995,Dielectric properties of partially saturated rocks:Energy&Fuels,9(3),413-419.
Kavian,M.,Slob,E.C.,and Mulder,W.A.,2012,Anew empirical complex electrical resistivity model:Geophysics,77(3),185-191.
Knight,R.J.,and Nur,A.,1987,The dielectric constant of sandstones 60kHz to 4MHz:Geophysics,52(5),644-654.
Koelman,J.M.V.A.,and De Kuijper,A.,1997,An effective medium model for the electric conductivity of an N-component anisotropic percolating mixture:Physica A,247(1),10-22.
Lesmes,D.P.,and Kevin,M.F.,2001,Influence of pore fluid chemistry on the complex conductivity and induced polarization response of Berea sandstones:Journal of Geophysics Research,106(B3),4079-4090.
Li,G.N.,Deng,J.Z.,and Chen,H.,2015,The applicability study on modified Dias complex resistivity model to the Xiangshan Uranium ore-field Chinese:Journal of Engineering Geophysics,12(6),732-740.
Li,J.J.,Deng,S.G.,Fan,Y.R.,et al.,2005,Study on influential factors on core’s complex resistivity:Well Logging Technology,29(1),11-14.
Liu,H.Q.,Jie,T.,Li,B.,et al.,2017,Study of the lowfrequency dispersion of permittivity and resistivity in tight rocks:Journal of Applied Geophysics,143,141-148.
Major,J.,and Silk,J.,1981,Restrictions on the use of Cole-Cole dispersion models in complex resistivity interpretation:Geophysics,46(6),916-931.
Pan,B.Z.,Li,M.,and Zhang,R.,2016,CRI model and Maxwell-Garnett model of saturated rocks’dielectric constant:Well Logging Technology,40(3),257-261.
Siddharth,M.,Martin,G.,Lv,L.,et al.,2016,Dielectric effects in pyrite-rich clays on multifrequency induction logs and equivalent laboratory core measurements:57th SPWLA Annual Logging Symposium,Reykjavik,Iceland.
Song,Y.J.,Wang,C.,Tang,X.M.,et al.,2009,Symmetrical effective medium complex resistivity model for water flooded shaly sand formation:Journal of Daqing Petroleum Institute,33(3),13-17.
Sun,B.,Tang,X.G.,Xiang,K.,et al.,2016,The analysis and measure on complex resistivity parameters of shaly sands in high temperature and high pressure:Chinese Journal of Engineering Geophysics,13(3),277-283.
Tabarovsky,L.,Georgi,D.,2000,Effect of pyrites on HDIL measurements:41th SPWLA Annual Logging Symposium,Paper G.
Thomas,I.N.,and Fran?ois,B.,2006,Numerical modeling of complex resistivity effects on a homogeneous half-space at low frequencies:Geophysical Prospecting,54(3),261-271.
Tong,M.S.,Li,L.,Jiang,Y.Z.,et al.,2005,Experimental study of complex resistivity of patialwater saturated shaly sands under reservoir condition:Petroleum Instruments,19(1),22-24.
Vinegar,H.J.,Waxman,M.H.,1984,Induced polarization of shaly sands:Geophysics,49(8),1267-1287.
Xiao,Z.S.,2005,Frequency dispersion properties analyzing and numerical modeling in complex resistivity logging:PhD Thesis,Zhejiang University.
Xiao,Z.S.,Xu,S.Z.,Luo,Y.Z.,et al.,2006,Complex resistivity dispersion properties experiment of shaly sands:Geological Journal of China Universities,12(1),123-130.
Zhao,Y.S.,Xiao,Z.S.,Qiu,Y.P.,et al.,2014,Experiment on rock-electrical parameter dispersion characteristics of special lithology:Journal of Oil and Gas Technology,36(12),98-101.
Al-Mjeni,R.,Günzel,F.,Jing,X.D.,et al.,2002,The influence of clay fraction on the complex impedance of shaly sands:Society of Core Analysts Conference,September,SCA 2002-29,1-12.
Clavier,C.,Heim,A.,and Scala,C.,1976,Effect of pyrite on resistivity and other logging measurements:17th SPWLA Annual Logging Symposium,Paper HH.
Clennell,M.B.,Josh,M.,Esteban,L.,et al.,2010,The influence of pyrite on rock electrical properties a case study from NW Australian gas reservoirs:51th SPWLA Annual Logging Symposium Australia,Paper UUU.
De Kuijper,A.,Sandor,R.K.J.,Hofman,J.P.,et al.,1996,Electrical conductivities in oil-bearing shaly sand accurately described with the SATORI saturation model:The Log Analyst,37(5),22-31.
Fan,Y.R.,Lu,J.M.,Wang,G.H.,et al.,1994,Experimental study on the dispersion of rock resistivity:Journal of the University of Petroleum,18(1),17-23.
Garrouch,A.A.,and Sharma,M.M.,1994,The influence of clay content,salinity,stress and wettability on the dielectric properties of brine-saturated rocks 10Hz to10MHz:Geophysics,59(6),909-917.
Garrouch,A.A.,and Sharma M.M.,1995,Dielectric properties of partially saturated rocks:Energy&Fuels,9(3),413-419.
Kavian,M.,Slob,E.C.,and Mulder,W.A.,2012,Anew empirical complex electrical resistivity model:Geophysics,77(3),185-191.
Knight,R.J.,and Nur,A.,1987,The dielectric constant of sandstones 60kHz to 4MHz:Geophysics,52(5),644-654.
Koelman,J.M.V.A.,and De Kuijper,A.,1997,An effective medium model for the electric conductivity of an N-component anisotropic percolating mixture:Physica A,247(1),10-22.
Lesmes,D.P.,and Kevin,M.F.,2001,Influence of pore fluid chemistry on the complex conductivity and induced polarization response of Berea sandstones:Journal of Geophysics Research,106(B3),4079-4090.
Li,G.N.,Deng,J.Z.,and Chen,H.,2015,The applicability study on modified Dias complex resistivity model to the Xiangshan Uranium ore-field Chinese:Journal of Engineering Geophysics,12(6),732-740.
Li,J.J.,Deng,S.G.,Fan,Y.R.,et al.,2005,Study on influential factors on core’s complex resistivity:Well Logging Technology,29(1),11-14.
Liu,H.Q.,Jie,T.,Li,B.,et al.,2017,Study of the lowfrequency dispersion of permittivity and resistivity in tight rocks:Journal of Applied Geophysics,143,141-148.
Major,J.,and Silk,J.,1981,Restrictions on the use of Cole-Cole dispersion models in complex resistivity interpretation:Geophysics,46(6),916-931.
Pan,B.Z.,Li,M.,and Zhang,R.,2016,CRI model and Maxwell-Garnett model of saturated rocks’dielectric constant:Well Logging Technology,40(3),257-261.
Siddharth,M.,Martin,G.,Lv,L.,et al.,2016,Dielectric effects in pyrite-rich clays on multifrequency induction logs and equivalent laboratory core measurements:57th SPWLA Annual Logging Symposium,Reykjavik,Iceland.
Song,Y.J.,Wang,C.,Tang,X.M.,et al.,2009,Symmetrical effective medium complex resistivity model for water flooded shaly sand formation:Journal of Daqing Petroleum Institute,33(3),13-17.
Sun,B.,Tang,X.G.,Xiang,K.,et al.,2016,The analysis and measure on complex resistivity parameters of shaly sands in high temperature and high pressure:Chinese Journal of Engineering Geophysics,13(3),277-283.
Tabarovsky,L.,Georgi,D.,2000,Effect of pyrites on HDIL measurements:41th SPWLA Annual Logging Symposium,Paper G.
Thomas,I.N.,and Fran?ois,B.,2006,Numerical modeling of complex resistivity effects on a homogeneous half-space at low frequencies:Geophysical Prospecting,54(3),261-271.
Tong,M.S.,Li,L.,Jiang,Y.Z.,et al.,2005,Experimental study of complex resistivity of patialwater saturated shaly sands under reservoir condition:Petroleum Instruments,19(1),22-24.
Vinegar,H.J.,Waxman,M.H.,1984,Induced polarization of shaly sands:Geophysics,49(8),1267-1287.
Xiao,Z.S.,2005,Frequency dispersion properties analyzing and numerical modeling in complex resistivity logging:PhD Thesis,Zhejiang University.
Xiao,Z.S.,Xu,S.Z.,Luo,Y.Z.,et al.,2006,Complex resistivity dispersion properties experiment of shaly sands:Geological Journal of China Universities,12(1),123-130.
Zhao,Y.S.,Xiao,Z.S.,Qiu,Y.P.,et al.,2014,Experiment on rock-electrical parameter dispersion characteristics of special lithology:Journal of Oil and Gas Technology,36(12),98-101.