石油物探2025，Vol.64Issue(2)：328-339,12.DOI:10.12431/issn.1000-1441.2023.0344
页岩气储层高角度裂缝指示因子地震反演方法
Seismic inversion of high-angle fracture indicator for shale gas reservoirs
摘要
Abstract
It is difficult to use a vertical transverse isotropy(VTI)and a horizontal transverse isotropy(HTI)model to characterize fractured shale gas reservoirs with horizontal bedding and several groups of parallel high-angle fractures.However,an orthorhombic anisotropy(OA)model is a feasible alternative.Based on the anisotropic characteristics of high-angle fractures described using the reflectivity equation,an indicator that represents the intensity of high-angle fractures is proposed.We derive an azimuthal elastic impedance equation containing a fracture indicator for OA media from the approximate equation of OA reflection coefficient and an equivalent OA parameter.We also establish a method to invert fracture indicator and fracture azimuthal elastic impedance.To improve the stability of the inversion,the derived azimuthal elastic impedance equation is rewritten in a two-parameter form.A model-based iterative least-squares inversion is used to achieve the robust estimation of fracture indicator and fracture azimuth.A model test demonstrates the reliable estimation of fracture indicator and fracture azimuth even at the signal-to-noise ratio of 2.A practical application also yields reliable predictions.This method is a useful tool to predict shale gas reservoirs with high-angle fractures.关键词
页岩气储层/高角度裂缝/OA介质/裂缝指示因子/裂缝方位Key words
shale gas reservoir/high-angle fracture/OA medium/fracture indicator/fracture azimuth分类
地质学引用本文复制引用
李然,张广智,李胜军,高建虎,李林,严彬..页岩气储层高角度裂缝指示因子地震反演方法[J].石油物探,2025,64(2):328-339,12.基金项目
国家自然科学基金项目(42074136,U19B2008,U19B6003,41674130)和中国石油前瞻性基础性项目(2021DJ0606)共同资助. This research is financially supported by the National Natural Science Foundation of China(Grant Nos.42074136,U19B2008,U19B6003,41674130)and the PetroChina Prospective,Basic and Strategic Technology Research Project(Grant No.2021DJ0606). （42074136,U19B2008,U19B6003,41674130）
