摘要
在长波长假设下,薄互层是一种典型的横向各向同性介质;长波长各向异性假设使得薄互层复杂结构反演成为可能。通过综述长波长假设下薄互层等效各向异性的理论发展、数值模拟和物理实验,发现该理论的适用条件较为严苛:对于韵律型薄互层,波长与互层单元厚度的比值需大于等于10;对于随机型薄互层,需满足等效的平均长度远大于单层厚度,且远小于主波长的条件。综合分析与总结薄互层等效各向异性理论研究进展发现:韵律型薄互层的等效各向异性理论与薄互层的互层结构、波长与互层单元或单层厚度比值、薄储层内部的物性差异等因素密切相关;随机型薄互层的等效各向异性理论相较于韵律型薄互层更为复杂,除与上述条件有关外,还应考虑等效的平均长度与非均匀性尺度、主波长的关系。
In seismic exploration,interbed deposits occur as thin layered or interbed formations which are typically described as anisotropic media or transverse isotropic media at long wavelengths.Based on a review of theoretical developments,numerical simulations,and physical experiments,it was found that very strict conditions need to be met to evaluate an equivalent anisotropy.In particular,for a rhythmic thin interbed,the ratio of the wavelength to the thickness of the interbed needs to be at least ten.For a stochastic thin interbed,the average length needs to be much larger than the thickness of the individual layers and much smaller than the main wavelength.Additionally,it was found that the equivalent anisotropy of a rhythmic thin interbed is closely related to the ratio of the wavelength to the thickness of the interbedded unit or layer,but also to the difference in physical property of thin reservoir.Finally,to evaluate an equivalent anisotropy for a stochastic thin interbed,the relationships among the average length,inhomogeneity scale,and main wavelength need to be accounted for.
作者
李佳欣
杨春
王赟
LI Jiaxin;YANG Chun;WANG Yun(School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China)
出处
《石油物探》
EI
CSCD
北大核心
2021年第2期224-237,共14页
Geophysical Prospecting For Petroleum
基金
国家自然科学基金项目(U1839208,41425017,41604119,41574126)
中国石油化工股份有限公司研发项目(P18070-5)
中国石油化工股份有限公司西北分公司研发项目(34400008-18-ZC0607-0030,34400008-18-ZC0607-0031)共同资助。
关键词
长波长假设
薄互层
横向各向同性
韵律型
随机型
等效各向异性
long-wavelength assumption
thin interbed
transversely isotropic
rhythmic medium
stochastic medium
equivalent anisotropy
