Estimating annulus sealing properties using the flexural wave spectrum in pitch-catch well-logging

IF 3.8 2区物理与天体物理 Q1 ACOUSTICS

Ultrasonics Pub Date : 2024-10-28 DOI:10.1016/j.ultras.2024.107491

Sander Bøe Thygesen , Tore Lie Sirevaag , Sven Peter Näsholm

{"title":"Estimating annulus sealing properties using the flexural wave spectrum in pitch-catch well-logging","authors":"Sander Bøe Thygesen , Tore Lie Sirevaag , Sven Peter Näsholm","doi":"10.1016/j.ultras.2024.107491","DOIUrl":null,"url":null,"abstract":"<div><div>Safe oil and gas well operations require appropriate sealing of the annulus casing. Pitch-catch ultrasound logging measurements can be used for well-barrier inspection. In the analysis of such data, an important aspect is to determine whether there is cement or mud behind the casing.</div><div>This paper presents a data processing approach to differentiate between fluid and solid behind the casing from pitch-catch datasets. It is based on the spectral signature of the casing flexural wave, in which a notch-like dip might be observed. This dip is understood to occur in most solid annulus scenarios. However, when the annulus velocity exceeds a certain limit or is below a threshold, a dip is not produced. The frequency where the dip occurs is associated with an overlap between the flexural phase-velocity and the annulus P-wave velocity. This is exploited by picking the notch frequency, and then its value is used to estimate the annulus material P-wave velocity.</div><div>On the basis of this insight, a method for distinguishing solids from fluids is presented. The outcome is a binary algorithm that detects a dip (or no dip), and which in addition differentiates between annulus materials using the estimated velocity. In addition, we analyze the accuracy of the velocity estimation. It is straightforward to adopt this in an operational setting. This paper demonstrates the performance and accuracy of the algorithm for both simulated data and field recordings.</div></div>","PeriodicalId":23522,"journal":{"name":"Ultrasonics","volume":"146 ","pages":"Article 107491"},"PeriodicalIF":3.8000,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ultrasonics","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0041624X24002543","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ACOUSTICS","Score":null,"Total":0}

引用次数: 0

Abstract

Safe oil and gas well operations require appropriate sealing of the annulus casing. Pitch-catch ultrasound logging measurements can be used for well-barrier inspection. In the analysis of such data, an important aspect is to determine whether there is cement or mud behind the casing.

This paper presents a data processing approach to differentiate between fluid and solid behind the casing from pitch-catch datasets. It is based on the spectral signature of the casing flexural wave, in which a notch-like dip might be observed. This dip is understood to occur in most solid annulus scenarios. However, when the annulus velocity exceeds a certain limit or is below a threshold, a dip is not produced. The frequency where the dip occurs is associated with an overlap between the flexural phase-velocity and the annulus P-wave velocity. This is exploited by picking the notch frequency, and then its value is used to estimate the annulus material P-wave velocity.

On the basis of this insight, a method for distinguishing solids from fluids is presented. The outcome is a binary algorithm that detects a dip (or no dip), and which in addition differentiates between annulus materials using the estimated velocity. In addition, we analyze the accuracy of the velocity estimation. It is straightforward to adopt this in an operational setting. This paper demonstrates the performance and accuracy of the algorithm for both simulated data and field recordings.

查看原文本刊更多论文

在间距捕捉测井中利用挠曲波谱估算环空密封性能。

油气井的安全作业要求对环形套管进行适当的密封。间距捕捉超声波测井测量可用于井障检查。在分析此类数据时，一个重要的方面是确定套管后面是水泥还是泥浆。本文介绍了一种数据处理方法，用于从螺距捕捉数据集中区分套管后的流体和固体。该方法基于套管挠曲波的频谱特征，其中可能会观察到类似凹槽的倾角。据了解，在大多数固体环空情况下都会出现这种凹陷。然而，当环空速度超过一定限度或低于阈值时，就不会产生凹陷。出现凹陷的频率与挠曲相速度和环面 P 波速度之间的重叠有关。利用这一点，我们可以选取陷波频率，然后用其值来估算环面材料的 P 波速度。在此基础上，提出了一种区分固体和流体的方法。该方法是一种二进制算法，可检测凹陷（或无凹陷），并利用估算的速度区分环状材料。此外，我们还分析了速度估算的准确性。这种算法可以直接应用于实际工作中。本文展示了该算法在模拟数据和现场记录方面的性能和准确性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Ultrasonics 医学-核医学

CiteScore

7.60

自引率

19.00%

发文量

186

审稿时长

3.9 months

期刊介绍： Ultrasonics is the only internationally established journal which covers the entire field of ultrasound research and technology and all its many applications. Ultrasonics contains a variety of sections to keep readers fully informed and up-to-date on the whole spectrum of research and development throughout the world. Ultrasonics publishes papers of exceptional quality and of relevance to both academia and industry. Manuscripts in which ultrasonics is a central issue and not simply an incidental tool or minor issue, are welcomed. As well as top quality original research papers and review articles by world renowned experts, Ultrasonics also regularly features short communications, a calendar of forthcoming events and special issues dedicated to topical subjects.