High gas-saturation reservoir prediction based on frequency-dependent AVO inversion
LUO Xin1, CHEN Xuehua1,2, ZHANG Jie1, JIANG Wei1, SUN Leiming3, and XIAO Wei3
1. Key Laboratory of Earth Exploration and Information Techniques, Ministry of Education, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
2. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
3. Data Processing Company, Geophysical Branch, China Oilfield Services Limited, CNOOC, Zhanjiang, Guangdong 524057, China
Abstract:Elastic parameters obtained by conventional pre-or post-stack inversions are not sensitive to gas saturation of reservoirs.Therefore,we use dispersion parameters obtained by frequency-dependent AVO inversion to predict high gas-saturation reservoirs.First the influence of sand-reservoir saturation on viscosity of different fluid mixtures is analyzed with Refutas equation; and the influence of gas-saturation on velocity dispersion and attenuation is analyzed with the dynamic equivalent-medium theory and Wood's formula.Then the frequency-dependent AVO inversion is achieved based on f-μ-ρ AVO approximation; and the sensitive dispersion factor is optimized.The following phenomena are obtained in results:①Different fluids have different dispersion and attenuation,and dispersion and attenuation are dependent on water or gas saturation; ②The optimized dispersion factor is more sensitive to high gas-saturation reservoirs and less affected by the background,which can accurately depict the spatial distribution of high gas-saturation reservoirs.
Ostrander W.Plane-wave reflection coefficients for gas sands at non-normal angles of incidence[J].Geophy-sics,1984,49(10):1637-1648.
[2]
孙鹏远.多属性AVO分析及弹性参数反演方法研究[D].吉林长春:吉林大学,2004.SUN Pengyuan.Studies on the Method of Multi-Attribute AVO Analysis & Elastic Parameters Inversion[D].Jilin University,Changchun,Jilin,2004.
[3]
White J.Computed seismic speeds and attenuation in rocks with partial gas saturation[J].Geophysics,1975,40(2):224-232.
[4]
Chapman M.Frequency-dependent anisotropy due to meso-scale fractures in the presence of equant porosity[J].Geophysical Prospecting,2003,51(5):369-379.
[5]
Carcione J,Gurevich B,Santos J,et al.Angular and frequency-dependent wave velocity and attenuation in fractured porous media[J].Pure and Applied Geophysics,2013,170(11):1673-1683.
[6]
王峣钧,陈双全,王磊,等.基于斑块饱和模型利用地震波频散特征分析含气饱和度[J].石油地球物理勘探,2014,49(4):715-722.WNG Xiaojun,CHEN Shuangquan,WANG Lei,et al.Gas saturation analysis with seismic dispersion attribute based on patchy-saturation model[J].Oil Geophysical Prospecting,2014,49(4):715-722.
[7]
张广智,何锋,张佳佳,等.微观与介观波致流下的速度频散与衰减[J].石油地球物理勘探,2017,52(4):743-751.ZHANG Guangzhi,HE Feng,ZHANG Jiajia,et al.Velocity dispersion and attenuation at microscopic and mesoscopic wave-induced fluid flow[J].Oil Geophysical Prospecting,2017,52(4):743-751.
[8]
Chen X H,Zhong W L,He Z H,et al.Frequency-dependent attenuation of compressional wave and seismic effects in porous reservoirs saturated with multi-phase fluids[J].Journal of Petroleum Science and Engineering,2016,147(11):371-380.
[9]
Chen X H,Zhong W L,Gao G,et al.Numerical analysis of velocity dispersion in multi-phase fluid-saturated porous rocks[J].Pure and Applied Geophysics,2017,174(3):1219-1235.
[10]
李世凯,文晓涛,阮韵淇,等.基于黏滞-弥散理论的含气砂岩数值模拟与分析[J].石油地球物理勘探,2017,52(4):752-759.LI Shikai,WEN Xiaotao,RUAN Yunqi,et al.Sandstone gas reservoir simulation and analysis based on diffusive-viscous theory[J].Oil Geophysical Prospecting,2017,52(4):752-759.
[11]
李世凯,文晓涛,阮韵淇,等.基于White模型的含气砂岩垂直入射地震响应特征分析[J].石油物探,2017,56(2):232-239.LI Shikai,WEN Xiaotao,RUAN Yunqi,et al.Analysis of seismic response charateristics from vertical incident in sandstone gas reservoir based on the White model[J].Geophysical Prospecting for Petroleum,2017,56(2):232-239.
[12]
Chapman M,Maultzsch S,Liu E,et al.The effect of fluid saturation in an anisotropic multi-scale equant porosity model[J].Journal of Applied Geophysics,2003,54(3):191-202.
[13]
Chapman M,Liu E,Li X Y.The influence of abnormally high reservoir attenuation on the AVO signature[J].The Leading Edge,2005,24(11):1120-1125.
[14]
Chapman M,Liu E,Li X Y.The influence of fluid-sensitive dispersion and attenuation on AVO analysis[J].Geophysical Journal International,2006,167(11):191-202.
[15]
Wilson A,Chapman M,Li X Y.Frequency-dependent AVO inversion[C].SEG Technical Program Expanded Abstracts,2009,28:341-345.
[16]
吴小羊.基于频谱分析技术的频散AVO反演研究[D].北京:中国地质大学(北京),2010.WU Xiaoyang.Frequency Dependent AVO Inversion Using Spectral Decomposition Techniques[D].China University of Geosciences (Beijing),Beijing,2010.
[17]
Chen X H,He Z H,Gao G,et al.A fast combined method for fluid flow related frequency-dependent AVO modeling[C].SEG Technical Program Expanded Abstracts,2013,32:3454-3459.
[18]
高刚.含流体孔隙介质地震响应特征分析及流体识别方法[D].四川成都:成都理工大学,2013.GAO Gang.Analysis of Seismic Response Characteristics in Fluid-Saturated Porous Media and Study on Fluid Identification Method[D].Chengdu University of Technology,Chengdu,Sichuan,2013.
[19]
张震,印兴耀,郝前勇.基于AVO反演的频变流体识别方法[J].地球物理学报,2014,57(12):4171-4183.ZHANG Zhen,YIN Xingyao,HAO Qianyong.Frequency-dependent fluid identification method based on AVO inversion[J].Chinese Journal of Geophysics,2014,57(12):4171-4183.
[20]
罗鑫,陈学华,吕丙南,等.基于Gray反射系数的频变AVO反演[J].石油物探,2018,57(2):292-301.LUO Xin,CHEN Xuehua,LYU Bingnan,et al.Frequency-dependent AVO inversion based on Gray reflection coefficient formula[J].Geophysical Prospecting for Petroleum,2018,57(2):292-301.
[21]
钟晗,刘洋.频变AVO影响因素分析[J].石油地球物理勘探,2017,52(4):783-796.ZHONG Han,LIU Yang.Influence factors on frequency-dependent AVO[J].Oil Geophysical Prospecting,2017,52(4):783-796.
[22]
Li X Y,Wu X Y,Survey B G,et al.Quantitative estimation of gas saturation by frequency dependent AVO:Numerical,physical modelling and field studies[C].International Petroleum Technology Conference,2013.
[23]
Wu X Y,Li X Y,Chapman M,et al.Quantitative gas saturation estimation by frequency-dependent amplitude-versus-offset analysis[J].Geophysical Prospecting,2014,62(6):1224-1237.
[24]
Chen S Q,Chapman M,Wu X Y,et al.The application of quantitative gas saturation estimation based on the seismic wave dispersion inversion[J].Journal of Applied Geophysics,2015,120(3):81-95.
[25]
Maples R E.Petroleum Refinery Process Economics[M].Pennwell Books,2000.
[26]
Chapman M,Zatsepin S V,Crampin S.Derivation of a microstructural poroelastic model[J].Geophysical Journal International,2002,151(2):427-451.
[27]
Russell B H,Hedlin K,Hilterman F J.Fluid-property discrimination with AVO:a Biot-Gassmann perspective[J].Geophysics,2003,68(1):128-138.
[28]
陈学华,贺振华,黄德济.广义S变换及其时频滤波[J].信号处理,2008,24(1):28-31.CHEN Xuehua,HE Zhenhua,HUANG Deji.Generalized S transform and its time-frequency filtering[J].Signal Processing,2008,24(1):28-31.
[29]
Wiggins R,Kenny G S,Mcclure C D.Method for determining and displaying the shear wave reflectivities of a geologic formation[P].European,0113944.1983-01-17.
[30]
Gazdag J,Saguazzero P.Miguration of seismic data by phase-shift plus interpolation[J].Geophysics,1984,49(2):124-131.