Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil

In order to calibrate time-lapse quantitative interpretation, it is crucial to analyze saturation and pressure effects on seismic velocities. While the former is adequately modeled using Gassmann, the latter is mainly obtained by laboratory measurements, which can be affected by core damage. Weinves...

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Bibliographic Details
Main Authors: Grochau, Marcos, Gurevich, Boris
Other Authors: RIPED, Petro China
Format: Conference Paper
Published: University of Houston 2007
Online Access:http://hdl.handle.net/20.500.11937/17716
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author Grochau, Marcos
Gurevich, Boris
author2 RIPED, Petro China
author_facet RIPED, Petro China
Grochau, Marcos
Gurevich, Boris
author_sort Grochau, Marcos
building Curtin Institutional Repository
collection Online Access
description In order to calibrate time-lapse quantitative interpretation, it is crucial to analyze saturation and pressure effects on seismic velocities. While the former is adequately modeled using Gassmann, the latter is mainly obtained by laboratory measurements, which can be affected by core damage. Weinvestigate the magnitude of this effect on compressional wave velocities by comparing laboratory experiments and log measurements. We use Gassmann fluid substitution to obtain low-frequency saturated velocities from dry core measurements (thus mitigating the dispersion effects) taken at reservoir pressure. The analysis is performed for an unusual densely cored well from which 43 cores were extracted from a 45 meters thick turbidite reservoir. Comparison of these computed velocities with the sonic log measurements shows very good agreement. This confirms that for this particular region the effect of core damage on ultrasonic measurements is below the measurement error. Consequently stress sensitivity of elastic properties as obtained from ultrasonic measurements is adequate for quantitative interpretation of time-lapse seismic data.
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format Conference Paper
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institution Curtin University Malaysia
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last_indexed 2025-11-14T07:22:31Z
publishDate 2007
publisher University of Houston
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spelling curtin-20.500.11937-177162017-05-30T07:59:53Z Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil Grochau, Marcos Gurevich, Boris RIPED, Petro China In order to calibrate time-lapse quantitative interpretation, it is crucial to analyze saturation and pressure effects on seismic velocities. While the former is adequately modeled using Gassmann, the latter is mainly obtained by laboratory measurements, which can be affected by core damage. Weinvestigate the magnitude of this effect on compressional wave velocities by comparing laboratory experiments and log measurements. We use Gassmann fluid substitution to obtain low-frequency saturated velocities from dry core measurements (thus mitigating the dispersion effects) taken at reservoir pressure. The analysis is performed for an unusual densely cored well from which 43 cores were extracted from a 45 meters thick turbidite reservoir. Comparison of these computed velocities with the sonic log measurements shows very good agreement. This confirms that for this particular region the effect of core damage on ultrasonic measurements is below the measurement error. Consequently stress sensitivity of elastic properties as obtained from ultrasonic measurements is adequate for quantitative interpretation of time-lapse seismic data. 2007 Conference Paper http://hdl.handle.net/20.500.11937/17716 University of Houston restricted
spellingShingle Grochau, Marcos
Gurevich, Boris
Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title_full Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title_fullStr Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title_full_unstemmed Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title_short Effect of core damage on elastic properties for time-lapse interpretation, offshore Brazil
title_sort effect of core damage on elastic properties for time-lapse interpretation, offshore brazil
url http://hdl.handle.net/20.500.11937/17716