基于二氧化碳和液氮吸附、高压压汞和低场核磁共振的煤岩多尺度孔径表征

发布时间：2018-05-15 21:08

本文选题：煤层气 + 鄂尔多斯盆地东缘　；参考：《中国矿业》2017年04期

【摘要】：煤岩系统内发育有nm~mm级的多种孔裂隙,系统表征其内部孔隙结构特征对查明煤岩物性和煤层气产出规律极为重要。基于对鄂尔多斯盆地东缘不同地区的系统采样,采用低温二氧化碳和液氮吸附、高压压汞和低场核磁共振系统表征了研究区煤岩的孔径结构。结果表明,二氧化碳吸附适用于0.6~1nm的微孔,液氮的主体适用范围在1~20nm左右,压汞可表征18nm以上的孔径。根据进汞饱和度、退汞效率和孔隙度将研究区煤岩划分为7个小类,并对应分析了进汞-退汞曲线特征。基于核磁共振表征了不同镜质体反射率和不同埋深的煤岩孔径大小的分布和连通性,随反射率升高和埋深加大,微小孔的比例呈现增加的趋势。相关成果对解释东缘范围内的煤储层物性特征,系统查明不同尺度煤岩孔径分布特征具有一定的支撑作用。
[Abstract]:There are many kinds of pores and fractures of nm~mm grade developed in coal and rock system. It is very important to characterize the internal pore structure characteristics of coal rock and coalbed methane production law systematically in order to find out the physical properties of coal and rock and the law of coal bed methane production. Based on the systematic sampling of different areas in the eastern edge of Ordos Basin, the pore structure of coal and rock in the study area was characterized by low temperature carbon dioxide and liquid nitrogen adsorption, high pressure mercury injection and low field nuclear magnetic resonance (NMR) system. The results show that carbon dioxide adsorption is suitable for the micropores of 0.6~1nm, and the main application range of liquid nitrogen is about 1~20nm. The pore size above 18nm can be characterized by mercury injection. According to mercury saturation, mercury removal efficiency and porosity, coal and rock in the study area are divided into 7 subgroups, and the characteristics of mercury-de-mercury curve are analyzed. Based on nuclear magnetic resonance (NMR), the distribution and connectivity of pore size of coal and rock with different vitrinite reflectivity and different buried depth were characterized. With the increase of reflectivity and buried depth, the proportion of micropores increased. The relevant results can support the interpretation of the physical characteristics of coal reservoirs in the eastern margin and the systematic identification of pore size distribution characteristics of coal and rock at different scales.
【作者单位】：中国矿业大学(北京)地球科学与测绘工程学院;
【基金】：中国矿业大学(北京)大学生创新训练项目资助(编号:C201602022) 国家自然科学基金项目资助(编号:41272175) 国土资源部公益性行业科研专项资助(编号:201311015)
【分类号】：TE311

【相似文献】