Analytical solutions for dispersions and waveforms of acoustic logging in a cased hole

波形 声学 登录中 地质学 计算机科学 物理 电信 地理 雷达 林业
作者
Hua Wang,Tianlin Liu,Yunjia Ji
出处
期刊:Geophysics [Society of Exploration Geophysicists]
卷期号:89 (3): D159-D170
标识
DOI:10.1190/geo2023-0316.1
摘要

Acoustic logging is one of the most promising methods for the quantitative evaluation of cement bond conditions in cased holes. However, inefficient use of full-wave information yields unsatisfactory interpretation accuracy. Fundamentally, this is because the wavefield characteristics have not been thoroughly investigated under various cement bonding conditions. Thus, this study derives analytical solutions of wavefields for a single-cased-hole model and emphasizes the dispersion calculation algorithm. To solve the dispersion equation when solving for the poles of the propagating modes with real wavenumbers, we renormalize the Bessel function related to the borehole fluid by multiplying it with an attenuation factor. For leaky modes with complex wavenumbers, we develop a novel method to find local peaks of the matrix condition number (LPMCN) in the frequency domain to determine dispersion poles, avoiding the local optimization issues resulting from the traditional Gauss-Newton iteration method. Combining these two methods, we establish a fast and accurate workflow for evaluating the dispersion of all modes in cased holes using a relatively fast bisection method to manage the dispersion of the propagating modes and using the LPMCN method to derive the dispersion curves of leaky modes. Furthermore, all propagating modes are individually investigated in the monopole measurement by evaluating the residues of the real poles in a casing-free model. The analysis demonstrates that the first-order pseudo-Rayleigh wave (PR1) and inner Stoneley wave (ST1) are the two strongest modes. Finally, we focus on the waveforms and dispersion characteristics of the outer Stoneley wave (ST2) related to the fluid channel in the cement annulus. The results reveal that as the fluid thickness increases, the phase velocity of the ST2 mode decreases, and its amplitude increases. Therefore, the ST2 mode can potentially evaluate the thickness of the fluid channel in a cement annulus if an effective weak-signal-extraction method is used.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
Miracle_wh发布了新的文献求助10
1秒前
3秒前
3秒前
4秒前
4秒前
圆月弯刀完成签到 ,获得积分10
5秒前
坦率白萱应助DJANGO采纳,获得30
7秒前
露亮完成签到,获得积分10
8秒前
Bressanone发布了新的文献求助10
8秒前
9秒前
斯文的慕儿完成签到 ,获得积分10
11秒前
露亮发布了新的文献求助10
11秒前
11秒前
智慧少女不头秃完成签到,获得积分10
13秒前
33完成签到,获得积分10
14秒前
所所应助感谢有你采纳,获得10
16秒前
16秒前
17秒前
18秒前
乐乐应助anna采纳,获得10
21秒前
潇湘雪月发布了新的文献求助10
21秒前
21秒前
刘燕发布了新的文献求助10
22秒前
22秒前
23秒前
量子星尘发布了新的文献求助10
26秒前
俏皮芷蕊发布了新的文献求助10
26秒前
27秒前
30秒前
30秒前
31秒前
Rondab应助张学友采纳,获得10
34秒前
34秒前
anna发布了新的文献求助10
35秒前
37秒前
如约而至完成签到 ,获得积分10
37秒前
37秒前
38秒前
39秒前
39秒前
高分求助中
A new approach to the extrapolation of accelerated life test data 1000
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
‘Unruly’ Children: Historical Fieldnotes and Learning Morality in a Taiwan Village (New Departures in Anthropology) 400
Indomethacinのヒトにおける経皮吸収 400
Phylogenetic study of the order Polydesmida (Myriapoda: Diplopoda) 370
基于可调谐半导体激光吸收光谱技术泄漏气体检测系统的研究 350
Robot-supported joining of reinforcement textiles with one-sided sewing heads 320
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3989115
求助须知:如何正确求助?哪些是违规求助? 3531367
关于积分的说明 11253688
捐赠科研通 3269986
什么是DOI,文献DOI怎么找? 1804868
邀请新用户注册赠送积分活动 882078
科研通“疑难数据库(出版商)”最低求助积分说明 809105