文献类型：期刊文献

中文题名：云冈石窟不同类型砂岩的核磁共振T_2谱——压汞毛管压力换算C值研究

英文题名：The translation Rresearch of different types sandstone of Yungang Grottoes in NMR T_2-mercury capillary pressure

作者：周华[1,2];高峰[3];周萧[3];刘化冰[4];郭葆鑫[4];王昌燧[2]

第一作者：周华

机构：[1]北京联合大学应用文理学院;[2]中科院古脊椎动物与古人类研究所;[3]中国文化遗产研究院;[4]中国石油大学油气资源与探测国家重点实验室

第一机构：北京联合大学应用文理学院

年份：2013

期号：5

起止页码：2759-2766

中文期刊名：地球物理学进展

外文期刊名：Progress in Geophysics

收录：CSTPCD;;北大核心:【北大核心2011】；CSCD:【CSCD2013_2014】；

基金：国家科技支撑计划项目"石质文物保护关键技术研究"(2009BAK53B01)资助

语种：中文

中文关键词：核磁共振;孔径分布;毛管压力曲线;刻度C值;石质文物保护

外文关键词：NMR, pore size distribution, capillary pressure curves scale, value of C, stone conservation

摘要：随着石质文物保护研究的深入,石质文物孔隙结构及孔径分布的研究越来越被重视,目前评价岩石孔隙结构主要是利用实验室岩芯分析毛管压力曲线获得,实验方法有局限性和损害性.NMR T2分布与孔隙结构有直接关系,因而能获得毛管压力信息,进而获得样品的孔径分布信息.与传统的毛管压力测量相比,NMR测量更加快速,方便并损耗性较小.因此,从T2分布获得毛管压力信息评价岩石孔隙结构具有广阔的应用前景.文章通过岩石孔喉半径-核磁T2分布拟合发现,两者成很好的线性相关;通过毛管压力-进汞饱和度分布图比较发现,核磁共振T2分布计算的伪毛管压力曲线与实测毛管压力曲线在形态和变化趋势上都有较好的一致性;文章最后应用最大相关性原理数学方法,为T2谱换算孔隙半径分布图提供了新的方法,求得了T2弛豫时间与岩芯孔隙半径r之间的换算系数C.误差分析显示,此种转换方式下,压汞孔喉半径-毛管压力累积分布与核磁弛豫时间-伪毛管压力累积分布拟合效果较为理想,误差均低于15%.而通过C值刻度,可以采用时域核磁方法获取云岗石窟地区不同砂岩的孔径分布信息,为砂岩风化机理研究,水盐迁徙研究,砂岩加固效果研究提供新的思路.
With the deepening of stone cultural relics conservation, research on pore structure and pore size distribution of stone cultural relics attract more and more attention. The present method to analysis pore structure of rock is using the mercury capillary pressure curve in laboratory, but experimental methods have limitations and destructive. As the cultural heritage is non-renewable and precious, in order to analysis the pore structure micro- damage and sometimes in situ, the Time-domain Nuclear Magnetic Resonance and Mobile single-sided NMR is used in heritage conservation. NMR T2 distribution is directly related to the pore structure. Compared with the traditional capillary pressure measurements, the NMR measurement is more rapid, convenient, and less attrition. Therefore,obtain the capillary pressure information of rock pore structure from the T2 distribution has broad application prospects. In the article, the analysis show the rock pore throat radius and NMR 7＂2 distribution fit a good linear correlation; and capillary pressure-into the mercury saturation maps shows measured capillary pressure curve was consist in morphology and the trend of change with NMR T2 distribution calculated pseudo-capillary pressure curve; the report also used the maximum principle of mathematical methods, given an improved T2 spectrum conversion practical and effective new method of pore distribution map, and obtain a conversion factor C between the T2 relaxation time and core pore radius r. The error analysis shows that under the conversion method, the pipe pressure of the pressure mercury pore throat radius-gross cumulative distribution of the Time-domain analysis （TDA） of NMR pseudo-capillary pressure cumulative distribution fitting ideal, the error is less than 15%, and maybe the signal of bound water result by clay minerals in serious weathering stone and siltstone contribute to the error of fitting data. By e value scale, the time-domain NMR method can be used to establish different pore size distribution of sandstone in the Yungang Grottoes, it provide new ideas in research of sandstone weathering mechanism, damp and salt movement, sandstone consolidation.