基于纵横波弹性阻抗联合反演的储层流体检测方法
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摘要
叠前弹性阻抗反演是储层含油气检测的重要方法,仅用叠后纵波资料反演存在反演过程不稳定、精度低等问题。为此,文中提出了基于叠前纵横波弹性阻抗联合反演的储层流体检测方法。首先,通过敏感性对比分析选取了流体因子F_ρ,该流体因子敏感性与Russell流体因子接近,避免了计算纵横波速度比产生的误差;其次,借鉴Connolly弹性阻抗方法,推导了基于流体因子和岩性指示因子E_ρ的纵波和转换横波弹性阻抗方程;最后,通过弹性阻抗反演直接提取F_ρ及E_ρ进行流体检测。模型测试验证了该方法具有较好的稳定性,提高了反演精度。实际资料测试表明,该方法得到的F_ρ和E_ρ可以较好地区分岩性并识别流体,从而有效地进行储层流体检测。
Pre-stack elastic impedance inversion is an important method for oil and gas reservoir detection. Inversion only using the three parameters of post-stack PP-wave data can lead to instability and low accuracy. In this paper, a fluid detection method based on joint inversion of PP-and PS-wave elastic impedance is proposed. First, fluid factor Fρis selected through sensitivity comparison and analysis. Selection of this fluid factor can avoid the error from calculating the ratio of P-wave velocity and S-wave velocity, while it has a comparable sensitivity with Russell fluid factor. Then, elastic impedance equations of PP-wave and PS-wave based on fluid factor Fρand lithology indicator E_ρ are derived with reference to the Connolly elastic impedance principle. Finally, fluid factor Fρand lithology indicator E_ρ can be directly extracted for fluid detection with the elastic impedance inversion method. Model test shows that the proposed method presents good stability and can improve the accuracy of inversion results. Tests on real data also indicate that fluid factor and lithologic indicator obtained from this inversion method perform better in identifying fluid and distinguishing lithology, which contributes to effective reservoir fluid detection.
Pre-stack elastic impedance inversion is an important method for oil and gas reservoir detection. Inversion only using the three parameters of post-stack PP-wave data can lead to instability and low accuracy. In this paper, a fluid detection method based on joint inversion of PP-and PS-wave elastic impedance is proposed. First, fluid factor Fρis selected through sensitivity comparison and analysis. Selection of this fluid factor can avoid the error from calculating the ratio of P-wave velocity and S-wave velocity, while it has a comparable sensitivity with Russell fluid factor. Then, elastic impedance equations of PP-wave and PS-wave based on fluid factor Fρand lithology indicator E_ρ are derived with reference to the Connolly elastic impedance principle. Finally, fluid factor Fρand lithology indicator E_ρ can be directly extracted for fluid detection with the elastic impedance inversion method. Model test shows that the proposed method presents good stability and can improve the accuracy of inversion results. Tests on real data also indicate that fluid factor and lithologic indicator obtained from this inversion method perform better in identifying fluid and distinguishing lithology, which contributes to effective reservoir fluid detection.
引文
[1] SMITH G C,GIDLOW P M. Weighted stacking for rock property estimation and detection of gas[J]. Geophysical Prospecting,1987,35(9):993-1014.
[2] GARDENER G H F,GARDENER L W,GREGORY A R. Formation velocity and density:the diagnostic basis for stratigraphic traps[J].Geophysics,1974,39(6):770-780.
[3] RUSSELL B H,HEDLIN K,HILTERMAN F J,et al. Fluid-property discrimination with AVO:a Biot-Gassmann perspective[J]. Geophysics,2003,68(1):29-39.
[4] LARSEN J A, MARGRAVE G F, LU H X. AVO analysis by simultaneous PP and PS weighted stacking applied to 3C-3D seismic data[J]. SEG Technical Program Expanded Abstracts,1999,18(1):721-724.
[5]陈刚,杜启振,余鹏,等.纵波与转换横波联合AVO反演估计横波速度和密度[J].断块油气田,2015, 22(6):729-734.
[6]李春宁.多波联合AVA属性提取与油气预测[D].青岛:中国石油大学(华东),2014.
[7] HILTERMAN F J. Three-dimensional seismic modeling[J]. Geophysics,1970,35(6):1020-1037.
[8] CASTAGNA J P,SMITH S W. Comparisonof AVO indicators:Amodeling study[J]. Geophysics,1994,9(59):1849-1855.
[9] AKI K,RICHARDS P G. Quantitative seismology:theory and methods[M]. Hampshire United Kingdom:W H Freeman and Company,1980:20-40.
[10] CONNOLLY P. Elastic impedance[J]. The Leading Edge,1999,18(4):438-452.
[11]刘军,沈向存,任丽丹,等.塔里木盆地顺托果勒低隆区志留系隐藏性圈闭识别与描述:高分辨率储层预测技术在S1井三维区的应用[J].石油实验地质,2012,34(增刊1):12-16.
[12]李建青,蒲仁海,武岳,等.江苏黄桥地区龙潭组沉积相与有利储层预测[J].石油实验地质,2012,34(4):395-399.
[13]杨爱棠.地震地层学在沅江凹陷的应用[J].石油实验地质,1987,9(3):228-239.
[14]严永新,张驰,常炳章,等.准噶尔盆地春光区块地震预测技术应用[J].石油实验地质,2013,35(1):104-107.
[15]李明,金振华.地震反演技术在浅层岩性油藏勘探中的应用[J].断块油气田,1999,6(2):5-8.
[2] GARDENER G H F,GARDENER L W,GREGORY A R. Formation velocity and density:the diagnostic basis for stratigraphic traps[J].Geophysics,1974,39(6):770-780.
[3] RUSSELL B H,HEDLIN K,HILTERMAN F J,et al. Fluid-property discrimination with AVO:a Biot-Gassmann perspective[J]. Geophysics,2003,68(1):29-39.
[4] LARSEN J A, MARGRAVE G F, LU H X. AVO analysis by simultaneous PP and PS weighted stacking applied to 3C-3D seismic data[J]. SEG Technical Program Expanded Abstracts,1999,18(1):721-724.
[5]陈刚,杜启振,余鹏,等.纵波与转换横波联合AVO反演估计横波速度和密度[J].断块油气田,2015, 22(6):729-734.
[6]李春宁.多波联合AVA属性提取与油气预测[D].青岛:中国石油大学(华东),2014.
[7] HILTERMAN F J. Three-dimensional seismic modeling[J]. Geophysics,1970,35(6):1020-1037.
[8] CASTAGNA J P,SMITH S W. Comparisonof AVO indicators:Amodeling study[J]. Geophysics,1994,9(59):1849-1855.
[9] AKI K,RICHARDS P G. Quantitative seismology:theory and methods[M]. Hampshire United Kingdom:W H Freeman and Company,1980:20-40.
[10] CONNOLLY P. Elastic impedance[J]. The Leading Edge,1999,18(4):438-452.
[11]刘军,沈向存,任丽丹,等.塔里木盆地顺托果勒低隆区志留系隐藏性圈闭识别与描述:高分辨率储层预测技术在S1井三维区的应用[J].石油实验地质,2012,34(增刊1):12-16.
[12]李建青,蒲仁海,武岳,等.江苏黄桥地区龙潭组沉积相与有利储层预测[J].石油实验地质,2012,34(4):395-399.
[13]杨爱棠.地震地层学在沅江凹陷的应用[J].石油实验地质,1987,9(3):228-239.
[14]严永新,张驰,常炳章,等.准噶尔盆地春光区块地震预测技术应用[J].石油实验地质,2013,35(1):104-107.
[15]李明,金振华.地震反演技术在浅层岩性油藏勘探中的应用[J].断块油气田,1999,6(2):5-8.