基于核磁共振测量的页岩气游离吸附比例关系确定——以涪陵页岩气储层为例

发布时间：2018-11-09 10:18

【摘要】：对页岩岩心开展了不同条件下饱和油水的核磁共振观测对比研究,并基于饱和油的核磁T_2谱,确定了页岩有机孔中游离空间与吸附空间大小及比例。研究表明:(1)有机孔隙和无机孔隙的润湿性通过饱和油水的核磁响应得到体现,与自吸油状态下的核磁信号相比,干燥抽真空饱和油页岩的核磁T_2谱在大孔段信号明显增大,反映出干燥后黏土孔喉能够允许更多的油分子进入有机孔中,此时核磁T_2谱主要反映有机孔信号。(2)通过对地层条件下有机孔的模拟计算,确定了游离气和吸附气含量相等时对应的有机孔孔径大小,根据有机孔的核磁连续孔径分布,确定出储层游离气和吸附气所占比例。总体上,优质页岩气储层具有更大的核磁孔径响应分布及游离吸附比,对应着更好的资源潜力和产气能力。
[Abstract]:The nuclear magnetic resonance (NMR) observation and comparison of saturated oil and water in shale cores were carried out under different conditions. Based on the NMR T _ 2 spectra of saturated oil, the size and proportion of free space and adsorption space in shale organic pores were determined. The results show that: (1) the wettability of organic and inorganic pores is reflected by the nuclear magnetic response of saturated oil and water. The nuclear magnetic Tap2 spectrum of vacuum saturated oil shale dried by drying increases obviously in the large pore section, which indicates that more oil molecules can be allowed into the organic pore by the throat of the clay pore after drying. At this time, the NMR T _ 2 spectrum mainly reflects the organic pore signal. (2) through the simulation calculation of the organic pore under the formation condition, the pore size corresponding to the organic pore when the content of free gas and adsorption gas is equal is determined. According to the distribution of nuclear magnetic continuous pore size of organic pores, the proportion of free gas and adsorbed gas in reservoir is determined. On the whole, the high quality shale gas reservoir has larger nuclear magnetic pore size response distribution and free adsorption ratio, corresponding to better resource potential and gas production capacity.
【作者单位】：中国地质大学(武汉)地球物理与空间信息学院;中石化华北石油工程有限公司测井分公司;中国石化石油勘探开发研究院中国石化页岩油气富集机理及有效开发国家重点实验室;
【分类号】：P618.13

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