垂直正交裂缝储层的频变方位AVO响应计算及分析  

Calculation and analysis of frequency-dependent azimuthal AVO response in vertically orthogonally fractured reservoirs

作　　者：邢慧婷 冯晅[1] 刘财[1] 郭智奇[1] 逄硕 XING HuiTing;FENG Xuan;LIU Cai;GUO ZhiQi;PANG Shuo(College of Geo-Exploration Science and Technology,Jilin University,Changchun 130026,China;Ocean University of China,Qingdao 266100,China)

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]中国海洋大学,青岛266100

出　　处：《地球物理学报》2024年第12期4773-4793,共21页Chinese Journal of Geophysics

基　　金：国家重点研发项目(2022YFC3003402)资助。

摘　　要：非常规油气储层中裂缝参数对勘探与开发至关重要.裂缝发育程度和分布特征是影响储层油气运移的主要因素,故裂缝系统的属性在非常规油气储层预测中起着关键作用.为了精确地描述裂缝型储层的性质,基于Chapman多组裂缝岩石物理理论,本文建立了含两组垂直正交裂缝的频散岩石物理模型,并定量分析了孔隙度、裂缝密度及裂缝尺寸对含油饱和裂缝储层的频变各向异性特征的影响.同时,利用各向异性反射率法,研究了不同孔隙度、裂缝参数及薄层厚度条件下垂直正交裂缝砂岩储层的频变方位AVO响应特征.结果表明,在单界面反射模型中,PP波反射系数在低频段对孔隙度和裂缝参数较为敏感,其中孔隙度和裂缝尺寸的变化对反射PP波的频变AVO特征影响显著.在薄层反射模型中,薄层厚度和频变效应呈正相关变化.本研究为复杂各向异性裂缝储层的频变特性分析提供了基础,旨在提升非常规油气储层定量预测的准确性.In the exploration and development of unconventional oil and gas reservoirs,it is crucial to describe fracture parameters and hydrocarbon saturation.In these unconventional reservoirs,the fracture systems are fundamental in controlling oil and gas transport.To accurately describe the properties of fractured reservoirs,we constructed a frequency-dependent rock physics model based on the Chapman multi-set fracture rock physics theory.This model includes two sets of vertically orthogonal fractures.And we quantitatively analyzed the influence of porosity,fracture density and fracture size on the frequency-dependent anisotropic characteristics of oil-saturated fractured reservoirs.In addition,using the anisotropic reflectivity method,we studied the frequency-dependent azimuthal AVO response characteristics of vertically orthogonal fractured sandstone reservoirs under different conditions of porosity,fracture parameters,and thin-layer thickness.The results indicate that in a single-interface reflection model,the reflection coefficient of the PP wave is more sensitive to porosity and fracture parameters at the low frequencies.The Changes of porosity and fracture size significantly affect the frequency-dependent AVO characteristics of the reflected PP wave.In the thin-layer reflection model,there is a positive correlation between thin-layer thickness and frequency-dependent effects.This study provides a foundation for the frequency-dependent analysis of complex anisotropic fractured reservoirs and aims to improve the accuracy of quantitative predictions for unconventional oil and gas reservoirs.

关 键 词：垂直正交裂缝 岩石物理模型 砂岩储层 各向异性反射率法 频变方位AVO 

分 类 号：P631[天文地球—地质矿产勘探]