Sensitivity and error propagation in well-placement bed-boundary detection

Abstract

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2018Sensitivity and error propagation in well-placement bed-boundary detectionAuthors: Xiaoyan ZhongEttore MirtoJean-Michel DenichouRajan DuaXiaoyan ZhongSchlumbergerSearch for more papers by this author, Ettore MirtoSchlumbergerSearch for more papers by this author, Jean-Michel DenichouSchlumbergerSearch for more papers by this author, and Rajan DuaSchlumbergerSearch for more papers by this authorhttps://doi.org/10.1190/segam2018-2995520.1 SectionsSupplemental MaterialAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail AbstractOne of the challenging but critical aspects in well placement is to detect the bed boundary accurately. It has been found that estimation of bed boundary detection degrades when measurement errors are applied. This degradation either results in a lower estimate of the detection range, or can be expressed as a reduced confidence in detection at a given distance.For a well placement system, bed boundary detection is affected by both measurement noise and systematic error. Any claim of how far a tool can detect a bed boundary must be accompanied by an uncertainty assessment. The demand of a methodology for a complete sensitivity and error propagation analysis in bed boundary detection is inevitably compelling. In this paper, two techniques are elaborated for this purpose.We first present how to obtain a detection range color map with the resistivity variation of a formation layer and a shoulder layer based on the practical error model. We demonstrate how bed boundary detection is affected by the error, and a color map can provide a gauge of sensitivity under different resistivity contrasts for a well placement tool.The workflow for a full system modeling is then discussed; this method accounts for the noise and error propagation in both forward modeling and inversion. It represents the deliverables from a well placement system and provides the confidence level together with the detection capability.Presentation Date: Tuesday, October 16, 2018Start Time: 8:30:00 AMLocation: 212A (Anaheim Convention Center)Presentation Type: OralKeywords: well geosteering, electromagnetics, noise, logging while drillingPermalink: https://doi.org/10.1190/segam2018-2995520.1FiguresReferencesRelatedDetails SEG Technical Program Expanded Abstracts 2018ISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2018 Pages: 5520 publication data© 2018 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 27 Aug 2018 CITATION INFORMATION Xiaoyan Zhong, Ettore Mirto, Jean-Michel Denichou, and Rajan Dua, (2018), "Sensitivity and error propagation in well-placement bed-boundary detection," SEG Technical Program Expanded Abstracts : 724-728. https://doi.org/10.1190/segam2018-2995520.1 Plain-Language Summary Keywordswell geosteeringelectromagneticsnoiselogging while drillingPDF DownloadLoading ...