海域油气盖层叠前地震反演预测方法及应用  

Pre-Stack Seismic Inversion Prediction Method and Application for Marine Oil and Gas Cap Rocks

作　　者：郑轩 宗兆云 付亚群 骆坤 Zheng Xuan;Zong Zhaoyun;Fu Yaqun;Luo Kun(School of Geosciences,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Sinopec Exploration Company,Chengdu 610041,China)

机构地区：[1]中国石油大学(华东)地球科学学院,山东青岛266580 [2]中国石油化工股份有限公司勘探分公司,成都610041

出　　处：《吉林大学学报（地球科学版）》2024年第6期2128-2141,共14页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(42174139,41974119,42030103);崂山实验室科技创新计划(LSKJ202203406)。

摘　　要：盖层对有效储层刻画、储层质量评估和油气藏开发具有重要意义。现有的海域地震预测方法主要针对储层,缺乏对盖层空间展布的研究与分析,亟需建立海域油气盖层叠前地震反演预测方法,为海域油气盖层的地震预测提供技术支撑。因此,本文提出一种基于岩石物理约束的海域盖层岩相以及物性参数叠前地震预测方法,对海域盖层岩相以及物性参数的地震描述进行深入研究。首先,通过海域地层的岩石物理建模分析,优选海域油气盖层岩相以及物性敏感弹性参数。其次,基于岩石物理模型,分别推导岩相敏感参数以及物性参数直接表征的地震反射系数方程和弹性阻抗方程,为海域盖层岩相的空间展布地震刻画和物性参数的地震预测提供技术支撑。为了解决模型参数之间的相关性导致反演结果不稳定的问题,在地震预测过程中通过奇异值分解方法实现模型参数的去相关性,并在贝叶斯反演理论的框架下分别推导海域盖层敏感弹性参数、物性参数的反演目标函数。将该方法应用于实际资料,结果表明泊松阻抗预测精度可以达到95%,孔隙度预测精度可以达到85%,验证了海域油气盖层叠前地震反演预测方法的合理性与有效性。Cap rocks are of great significance for effective reservoir characterization,reservoir quality assessment,and oil and gas reservoir development.The existing marine seismic prediction methods mainly focus on reservoirs,lacking research and analysis on the spatial distribution of cap rocks.It is urgent to establish a pre-stack seismic inversion prediction method for marine oil and gas cap rocks to provide technical support for the seismic prediction of marine oil and gas cap rocks.Therefore,this paper proposes a pre-stack seismic prediction method for marine cap rock facies and physical property parameters based on rock physics constraints,and conducts an in-depth study on the seismic description of marine cap rock facies and physical property parameters.First,through the rock physics analysis of marine strata,the marine oil and gas cap rock facies and physical property sensitive elastic parameters are optimized.Secondly,based on the rock physics model,the seismic reflection coefficient equation and elastic impedance equation directly characterized by the lithofacies sensitive parameters and physical property parameters are derived respectively,providing technical support for the seismic characterization of the spatial distribution of the marine cap rock facies and the seismic prediction of the physical property parameters.In order to solve the problem of unstable inversion results caused by the correlation between model parameters,the singular value decomposition method is used to realize the decorrelation of model parameters in the seismic prediction process,and the inversion objective functions of sensitive elastic parameters and physical parameters of marine cap rocks are derived respectively under the framework of Bayesian inversion theory.This method is applied to actual data to verify the rationality and effectiveness of the pre-stack seismic inversion prediction method for marine oil and gas cap rocks.The results show that the Poisson impedance prediction accuracy can reach 95%,and the porosity prediction a

关 键 词：海域油气 盖层 孔隙度 泊松阻抗 叠前反演 岩石物理模型 

分 类 号：P631.4[天文地球—地质矿产勘探]