基于含气泡液体声波方程的海底冷泉数值模拟  

Numerical simulation of submarine cold seepage based on acoustic equation of bubbly liquid

作　　者：张闪闪 谷丙洛 任志明 段沛然 李振春[1] ZHANG ShanShan;GU BingLuo;REN ZhiMing;DUAN PeiRan;LI ZhenChun(School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,青岛266580

出　　处：《地球物理学报》2020年第9期3505-3519,共15页Chinese Journal of Geophysics

基　　金：国家科技重大专项(2016ZX05024-003-011)资助.

摘　　要：海底冷泉羽状流与海底天然气水合物的分布密切相关,对水合物稳定带的边界具有指示作用,是未来能源勘探的重要领域.研究海底冷泉羽状流的地震响应特征,对确定天然气水合物的储集区域及成藏环境等均有重要意义.当前获得海底冷泉羽状流的地震响应主要通过数值模拟进行,然而该过程所依据的含气泡介质声速模型及随机介质理论不能完整描述海底冷泉的物理性质,采用的声波方程也不适用于高频地震波数值模拟.为了准确地实现海底冷泉羽状流地震波数值模拟,精确分析其地震响应特征,本文提出利用Keller-Miksis气泡振动模型来描述气泡在声波作用下的运动状态,同时考虑气泡间的相互作用,建立海底冷泉气泡模型.在此基础上,本文创新性地采用含气泡液体声波方程进行海底冷泉高频地震波数值模拟.数值模拟结果表明,本文提出的方法能够实现海底冷泉羽状流地震响应的高精度数值模拟.Submarine bubble plumes in cold seepages are closely related to the distribution of natural gas hydrates,and they can indicate the boundary of the hydrate stable zone,which is an important area of energy exploration in the future.Studying the response characteristics of submarine cold seepage bubble plumes is of great significance to determine the gas hydrate reservoir area and to understand its formation and reservoir environment.At present,the seismic response of submarine cold seepage plume flow is mainly carried out by numerical simulation.However,the acoustic velocity model with bubble medium and random medium theory cannot describe the physical properties of cold seepage completely,and the acoustic wave equation adopted is not applicable for the numerical simulation of high frequency seismic waves.In order to accurately simulate the seismic response and analyze the seismic response characteristics of submarine cold seepages,Keller-Miksis bubble vibration model is proposed to describe the motion state of bubbles under the action of acoustic wave.Considering the interaction between bubbles,submarine cold seepage bubble model is established.On this basis,the acoustic wave equation of bubbly liquid is innovatively introduced into the high frequency seismic wave numerical simulation in submarine cold seepages.The numerical results indicate that the equation can accurately simulate submarine cold seepage plume flow.

关 键 词：海底冷泉 地震波数值模拟 含气泡液体 传播特性 

分 类 号：P738[天文地球—海洋地质]