摘要
对有代表性的低渗透储层密闭取岩心平行样进行原始润湿和强亲水岩心的T2截止值核磁共振离心实验标定,并将实验结果进行比较,分析2种不同润湿性条件下T2截止值的差异及影响因素。研究表明：强亲水岩心的T2截止值比对应保持原始润湿性岩心的T2截止值普遍偏小,强亲水5块岩心实测T2截止值的分布范围为9.64~13.89 ms,平均值为12.58 ms;保持原始润湿性5块岩心实测T2截止值的分布范围为11.57~20.03 ms,平均值为16.33 ms。由于润湿性的影响,原始润湿岩心饱和水T2谱比对应的强亲水岩心T2谱偏右,T2几何平均值增大。岩心渗透率越大,含油性越好,岩石越亲油,则原始润湿岩心T2谱越偏右,T2几何平均值越大,导致T2截止值增大。岩心渗透率越小,岩石孔喉越细小,由于毛管力作用,原始润湿岩心束缚水饱和度更高,导致对应的T2截止值更大。
The T2 cutoff values of original wetting cores and strong hydrophilic cores are tested respectively by using NMR,and the difference between them and the factors producing the difference are analyzed. It is shown that,the T2 cutoff values of strong hydrophilic cores are less than those of corresponding original wetting cores. The tested T2 cutoff values of 5 strong hydrophilic cores distribute in9. 64 ~ 13. 89 ms,their average value is 12. 58 ms; the tested T2 cutoff values of 5 corresponding original wetting cores distribute in11. 57 ~ 20. 03 ms,their average value is 16. 33 ms. Because of different wettability,T2 spectra of the saturated cores with the original wettability are more right than those of the saturated hydrophilic cores,and their T2 geometric mean is also greater. The higher the permeability of the original wetting cores is,the better the oil-bearing property of them is,the more lipophilic the cores are,then the more right the T2 spectra of the cores are and the greater the T2 geometric mean of them is also,which leads to T2 cutoff values of them greater. The less the permeability of the original wetting cores is,the smaller and finer the pores and throats in the cores are,then the higher the irreducible water saturation of the cores is due to capillary force,which leads to T2 cutoff values of them greater.
出处
《西安石油大学学报（自然科学版）》
CAS
北大核心
2015年第5期43-47,8,共5页
Journal of Xi’an Shiyou University（Natural Science Edition）
基金
国家科技重大专项(编号:2011ZX05013-006)
关键词
低渗透岩心
T2截止值
岩心润湿性
高速离心
核磁共振
low permeability core
T2cutoff value
core wettability
high speed centrifugation
NMR
