摘要
在天然气水合物(简称水合物)钻采过程中,动态监测水合物沉积物具有非常重要的现实意义和应用价值.常规探测方法只能判断水合物分解前的大致分布情况,很难获得水合物分解过程中固-液交界面的动态变化和图像.本文将热声耦合引入到水合物的钻采监测中,首次提出了在瞬态强脉冲激励下水合物产生瞬态相变、并激发相变热声信号的物理机制,导出了脉冲激励与声源之间的耦合方程,提出了基于滤波反投影算法的相变界面成像方法.建立了三维仿真模型,开展了电场和声场耦合分析,在强脉冲激励下求解出了热函数及声压分布.然后模拟超声换能器接收到的声信号,利用声信号对不同半径的水合物重建声源的分布,从声源图像得到水合物的相变界面位置信息.为水合物松散沉积物的研究提供了一种全新的探测方法.
In the drilling and production procession of natural gas hydrate,dynamic monitoring of hydrate sediments has very important practical significance and application value.Conventional detection methods can only judge the general distribution of hydrate before decomposition,and it is difficult to obtain the dynamic changes and images of solid-liquid interface in the process of hydrate’s decomposition.In this paper,the thermoacoustic coupling is introduced into monitoring hydrate.The physical mechanism of hydrate generating transient phase transition and exciting phase transition thermoacoustic signals under transient strong pulse is proposed for the first time,the coupling equation between pulse and acoustic source is derived,and the phase transition interface imaging method based on filtered back-projection algorithm is proposed.The three-dimensional simulation model is established,the coupling analysis of electric field and acoustic field is carried out,the heat function and acoustic pressure distribution are solved under strong pulse excitation.Then,the acoustic signals received by the ultrasonic transducer is simulated,and the acoustic signals are used to reconstruct the distribution of acoustic source for hydrate with different radius.The phase transition interface position information of hydrate is obtained from the acoustic source image.It provides a new detection method for the study of hydrate loose sediments.
作者
郭亮
曾彩虹
邢兰昌
王斌
GUO Liang;ZENG CaiHong;XING LanChang;WANG Bin(College of Control Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China)
出处
《地球物理学进展》
CSCD
北大核心
2023年第1期201-210,共10页
Progress in Geophysics
基金
山东省自然科学基金面上项目(ZR2021ME093)资助。
关键词
天然气水合物
热声成像
相变界面
动态监测
Natural gas hydrate
Thermoacoustic imaging
Phase transition interface
Dynamic monitoring
