Evaluation of pore size spectrum of gas shale reservoirs using low pressure nitrogen adsorption, gas expansion and mercury porosimetry: A case study from the Perth and Canning Basins, Western Australia
Evaluation of pore size spectrum of gas shale reservoirs using low pressure nitrogen adsorption, gas expansion and mercury porosimetry: A case study from the Perth and Canning Basins, Western Australia
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DOI：
10.1016/j.petrol.2013.11.022
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发表时间：
2013-12-01
影响因子：
--
通讯作者：
Al Hinai, Adnan
中科院分区：
文献类型：
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作者：
Labani, Mohammad Mandi;Rezaee, Reza;Al Hinai, Adnan
气页岩具有复杂的孔隙结构。页岩气孔隙系统的储气机理有游离气和吸附气两种。天然气页岩储层的纳米孔隙系统对天然气的储集，特别是对天然气的吸附具有显著的贡献。本文采用低压氮气吸附法、压汞法和气体膨胀法三种不同的方法对油页岩的孔隙结构进行了表征。压汞法和气体膨胀法长期以来一直被用于常规储层的表征，但低压氮气吸附最近被认为是一种用于气页岩评价的工具。所研究的气页岩样品来自西澳大利亚的珀斯和坎宁盆地。实例分析结果表明，Canning页岩样品的比表面积和微孔/中孔体积分别约为13 m2/g和1.4 cc/100 g，相对高于珀斯页岩样品的相同值，定量分析结果明确了所研究的气页岩样品的形状、尺寸和孔体积。然而，分析结果表明，从这些技术中提取的类似参数（如有效孔隙度或孔径分布（PSD））之间没有任何一致性;已经提出了几种解释来证明这种不一致性。研究结果还表明，目前用于气页岩孔隙系统表征的各种常用技术都存在一定的不足，不能单独用于气页岩孔隙系统表征。而将这些方法的结果结合起来，可以更准确地确定页岩的孔径谱。(C)2013爱思唯尔有限公司版权所有。
Gas shales have a complex pore structure. Mechanisms of gas storage in the gas shale pore system are in two ways, free gas and sorbed gas. The nanometer scaled pore systems of gas shale reservoirs have a prominent contribution for gas storage, especially for adsorbing gas onto their surfaces. In this study three different methods of low pressure nitrogen adsorption, mercury porosimetry and gas expansion were used for pore structure characterization of gas shales. Mercury porosimetry and gas expansion methods have been used for a long time in characterization of conventional reservoirs but low pressure nitrogen adsorption has been considered recently as a tool for gas shale evaluation. The studied gas shale samples are coming from the Perth and Canning Basins, Western Australia. Analyzing the results of case study shows that the Canning shale samples have the specific surface area and micro/mesopore volume around 13 m(2)/g and 1.4 cc/100 g, respectively, which are relatively higher than the same values for the Perth shale samples.Quantitative analysis of the obtained results clarifies the shape, size and pore volume of the studied gas shale samples. However analyzing the results shows that there is not any consistency between similar parameters like effective porosity or pore size distribution (PSD) extracted from these techniques; several explanations have been proposed for justification of this inconsistency. As well as the results of this study make it clear that each of the usual techniques applied for characterization of gas shale pore systems has some deficiencies and cannot be used alone for this purpose. Whereas, by combining the results of these methodologies pore size spectrum of gas shales can be determined in a more accurate way. (C) 2013 Elsevier B.V. All rights reserved.