天然气勘探与开发2025，Vol.48Issue(5)：25-36,12.DOI:10.12055/gaskk.issn.1673-3177.2025.05.003
基于方位各向异性属性的裂缝多参数表征
Multi-parameter characterization of fractures based on azimuthal anisotropy attributes
摘要
Abstract
To accurately characterize the parameters(e.g.density,azimuth,and connectivity)of small-to medium-scale fractures in tight sandstone reservoirs in the Jianyang block,central Sichuan Basin,based on the Rüger theory of anisotropy and the OVT-domain wide-azimuth seismic data,the characteristics of fractures in the fourth member of the Upper Triassic Xujiahe Formation(Xu-4 Member)in this study area were investigated through integrating the azimuthal anisotropy attribute G inversion and the stochastic discrete fracture modeling.Specifically,fracture-induced azimuth-varying signals were extracted by azimuth/gather-based anisotropic gradient inversion,fracture density and orientation were quantified using the elliptic fitting algorithm,and a multi-scale fracture network model was built with the constraints of logging and seismic data.The following results are obtained.First,the results of azimuthal anisotropy attribute G inversion coincide with the logging-derived fracture density by 85%,and the predicted principal azimuths for four verification wells including Well YQ105 correspond to the error lower than 14°.Second,the fracture modeling indicates that 2,894 dominant fractures are developed in the study area,and the density of secondary fractures associated with the NE-trending fault zone is significantly higher than that of the gentle tectonic zone.Third,fracture density is linearly correlated with ellipticity,and the spatial coincidence between high-value zone and image logging interpretation results reaches 90%.Fourth,the Fisher distribution parameter in the stochastic discrete fracture modeling can effectively characterize the fracture orientation concentration,and the consistency with the rose diagram around the well is 93%.It is concluded that the proposed technology breaks through the limitations in traditional characterization of small-to medium-scale fractures based on post-stack attributes,and provides a quantitative prediction as a viable geological support to sweet spot identification and optimal well placement in tight gas reservoirs.关键词
四川盆地川中地区/简阳区块坡折带/三叠系上统须家河组/各向异性/裂缝密度/椭圆拟合/裂缝方位/离散裂缝建模Key words
Central Sichuan Basin/Slope-break belt in Jianyang block/Upper Triassic Xujiahe Formation/Anisotropy/Fracture density/Ellipse fitting/Fracture azimuth/Discrete fracture modeling分类
能源科技引用本文复制引用
戴隽成,闫媛媛,陈康,彭浩天,杨广广,魏玮..基于方位各向异性属性的裂缝多参数表征[J].天然气勘探与开发,2025,48(5):25-36,12.基金项目
中国石油天然气集团有限公司科技专项"致密砂岩气藏提高采收率关键技术研究"(编号:2023ZZ25YJ01). （编号:2023ZZ25YJ01）
