气候变化领域集成服务门户(CCPortal): Calculating Effective Elastic Properties of Berea Sandstone Using the Segmentation-Less Method Without Targets

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DOI	10.1029/2019JB018680
	Calculating Effective Elastic Properties of Berea Sandstone Using the Segmentation-Less Method Without Targets
	Ikeda K.; Goldfarb E.J.; Tisato N.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	We propose a new method to compute elastic properties of rocks from computed tomography (CT) images. A CT volume captures X-ray attenuation, which is scaled in a CT number unit. Our method improves an existing segmentation-less method where the CT volume is directly converted to elastic property arrays without using segmentation. A drawback of the existing segmentation-less method is that it typically requires to scan physical targets of known density along with the sample. Targets map a CT volume into petrophysical property arrays by comparing the CT numbers of the sample with those of the targets. We introduce a segmentation-less workflow that no longer requires targets but uses pseudotargets that are defined within the sample. Pseudotargets are composed of extrema CT numbers in the CT volume. We assume that regions containing extrema CT numbers represent pristine materials. The average CT numbers of such regions are paired to the pseudotarget densities to create a CT number-to-density conversion function. After density-to-porosity and porosity-to-elastic properties conversion, we simulate wave propagation on two Berea sandstone cores to estimate effective P and S wave velocities. To assess uncertainty, computed velocities are compared to laboratory measurements. We benchmark our technique against a segmentation-less method, as well as the more commonly used segmentation-based method. Among the three methods, the segmentation-less method without targets yields the least absolute velocity error of 4.5%, whereas segmentation and segmentation-less method yield +29% and +4.7% error, respectively. We conclude that the segmentation-less method without targets can efficiently compute elastic properties of rocks from CT volumes, serving as a technique to create better subsurface models. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	algorithm; CT-scan; digital rock physics; numerical modeling; ultrasonic measurement
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187808
作者单位	Jackson School of Geosciences, The University of Texas at Austin, Austin, TX, United States; Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON, Canada
推荐引用方式 GB/T 7714	Ikeda K.,Goldfarb E.J.,Tisato N.. Calculating Effective Elastic Properties of Berea Sandstone Using the Segmentation-Less Method Without Targets[J],2020,125(6).
APA	Ikeda K.,Goldfarb E.J.,&Tisato N..(2020).Calculating Effective Elastic Properties of Berea Sandstone Using the Segmentation-Less Method Without Targets.Journal of Geophysical Research: Solid Earth,125(6).
MLA	Ikeda K.,et al."Calculating Effective Elastic Properties of Berea Sandstone Using the Segmentation-Less Method Without Targets".Journal of Geophysical Research: Solid Earth 125.6(2020).