Brittleness index of coal from the Upper Silesian Coal Basin

IF 0.9 4区地球科学 Q4 GEOCHEMISTRY & GEOPHYSICS

Acta Geodynamica et Geomaterialia Pub Date : 2021-03-03 DOI:10.13168/AGG.2021.0007

Rafał Moska

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引用次数: 1

Abstract

A growing interest in the field of coal bed methane (CBM) extraction in Poland shows the demand for rock mechanics data, used to design hydraulic fracturing operations. The elastic response of the rock is typically determined by sonic logging calibrated with laboratory tests. This paper presents the laboratory ultrasonic measurements of the core samples, performed to determine the elastic moduli and brittleness index (BI) of the coal. Tests were performed on 20 core plugs from four coal mines located in the central and southern part of the Upper Silesian Coal Basin (USCB), Poland, characterized by varied maceral composition and mineral additives. The samples were cored out in three directions: perpendicular, parallel, and at a 45° angle to the bedding planes, and tested with the given effective pressure. The majority of the samples were saturated by water with a potassium chloride additive (swelling inhibitor). A Pand S-wave velocity upward trend was observed when the mineral content in the samples increased. Elevated velocities in samples of high mineral content resulted in exceeding the Ed to vd limits for coal as proposed in literature. With increased BI, upward trends in the liptinite and inertinite content as well as a downward trend in the vitrinite content were observed. The dynamic elastic moduli of the measured samples were compared to the available literature data. ARTICLE INFO

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上西里西亚煤盆地煤的脆性指数

波兰对煤层气开采领域的兴趣日益增长，这表明对用于设计水力压裂作业的岩石力学数据的需求。岩石的弹性响应通常通过实验室测试校准的声波测井来确定。本文介绍了岩心样品的实验室超声波测量，用于确定煤的弹性模量和脆性指数（BI）。对位于波兰上西里西亚煤盆地（USCB）中部和南部的四个煤矿的20个岩芯塞进行了测试，其特征是不同的显微组分和矿物添加剂。样品在三个方向上取芯：垂直、平行和与层面成45°角，并在给定的有效压力下进行测试。大多数样品被含有氯化钾添加剂（溶胀抑制剂）的水饱和。当样品中矿物含量增加时，观察到Pand S波速度呈上升趋势。高矿物含量样品中的速度升高导致超过了文献中提出的煤的Ed至vd限值。随着BI的增加，观察到脂质组和惰质组含量呈上升趋势，镜质组含量也呈下降趋势。将测量样品的动态弹性模量与现有文献数据进行比较。文章信息

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来源期刊

Acta Geodynamica et Geomaterialia 地学-地球化学与地球物理

CiteScore

2.30

自引率

0.00%

发文量

期刊介绍： Acta geodynamica et geomaterialia (AGG) has been published by the Institute of Rock Structures and Mechanics, Czech Academy of Sciences since 2004, formerly known as Acta Montana published from the beginning of sixties till 2003. Approximately 40 articles per year in four issues are published, covering observations related to central Europe and new theoretical developments and interpretations in these disciplines. It is possible to publish occasionally research articles from other regions of the world, only if they present substantial advance in methodological or theoretical development with worldwide impact. The Board of Editors is international in representation.