HTI介质下五维地震脆性稳定预测方法研究

Robust HTI brittleness prediction using 5D seismic data

中国石油化工股份有限公司胜利油田分公司物探研究院,山东东营257022

Geophysical Research Institute,Sinopec Shengli Oilfield Company,Dongying 257022,China

岩石的脆性性质是页岩油气藏勘探开发过程中工程甜点预测的重要指标之一。以横向各向同性介质(HTI)为例,建立了各向异性假设下的脆性指示因子与背景杨氏模量、背景泊松比及各向异性参数的关系,形成了五维地震脆性稳定预测方法。首先,基于各向同性假设预测储层的杨氏模量和泊松比;其次,基于复频域反演获得各向异性参数的低频信息作为初始模型,结合方位振幅差异反演技术稳定预测储层的3个各向异性参数;最后,通过背景杨氏模量和泊松比以及各向异性参数计算各向异性储层的脆性指示因子,实现HTI介质脆性的稳定预测。该方法可以充分利用宽频地震数据的低频信息,并将六参数直接反演转化为二次三参数反演,理论上提升了反演过程的稳定性。实际资料应用结果表明,该方法针对页岩油的脆性预测具有良好的效果。

Rock brittleness is an important index in predicting sweet spots for shale oil and gas exploration and development.This study focuses on the robust brittleness prediction using 5D seismic data for the media with horizontal transverse isotropy (HTI),which is based on the relationships between the brittleness index under an anisotropy assumption and background Young's modulus,background Poisson's ratio,and anisotropy parameters.Firstly,we predict the Young's modulus and Poisson's ratio of isotropic media.Secondly,we use low-frequency information of anisotropy parameters derived from a complex frequency domain inversion as initial models and stably predict three anisotropy parameters through an azimuthal amplitude difference inversion.Finally,we achieve the robust prediction of HTI brittleness index based on the background Young's modulus,Poisson's ratio,and anisotropy parameters.The proposed method effectively utilizes low-frequency information from broadband seismic data and converts the direct six-parameter inversion into two three-parameter inversions,which theoretically improves the stability of the inversion process.Actual data application demonstrates the good effects of shale oil brittleness prediction.

中国石油化工股份有限公司科研项目(P21061-2)资助。

10.12431/issn.1000-1441.2025.64.01.012