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http://dx.doi.org/10.9720/kseg.2020.1.017

A Quality-control Experiment Involving an Optical Televiewer Using a Fractured Borehole Model  

Jeong, Seungho (Department of Earth and Environmental Sciences, Chungbuk National University)
Shin, Jehyun (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources)
Hwang, Seho (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources)
Kim, Ji-Soo (Department of Earth and Environmental Sciences, Chungbuk National University)
Publication Information
The Journal of Engineering Geology / v.30, no.1, 2020 , pp. 17-30 More about this Journal
Abstract
An optical televiewer is a geophysical logging device that produces continuous high-resolution full-azimuth images of a borehole wall using a light-emitting-diode and a complementary metal-oxide semiconductor image sensor to provide valuable information on subsurface discontinuities. Recently, borehole imaging logging has been applied in many fields, including ground subsidence monitoring, rock mass integrity evaluation, stress-induced fracture detection, and glacial annual-layer measurements in polar regions. Widely used commercial borehole imaging logging systems typically have limitations depending on equipment specifications, meaning that it is necessary to clearly verify the scope of applications while maintaining appropriate quality control for various borehole conditions. However, it is difficult to directly check the accuracy, implementation, and reliability for outcomes, as images derived from an optical televiewer constitute in situ data. In this study, we designed and constructed a modular fractured borehole model having similar conditions to a borehole environment to report unprecedented results regarding reliable data acquisition and processing. We investigate sonde magnetometer accuracy, color realization, and fracture resolution, and suggest data processing methods to obtain accurate aperture measurements. The experiment involving the fractured borehole model should enhance not only measurement quality but also interpretations of high-resolution and reliable optical imaging logs.
Keywords
optical televiewer; discontinuity; quality control; fractured borehole model;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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