核磁共振及微、纳米CT技术在致密储层研究中的应用

——以鄂尔多斯盆地长7段为例

高长海

中国石油大学（华东），山东 青岛 266580 中国石化胜利油田分公司现河采油厂，山东 东营 257000

China University of Petroleum, Qingdao 266580, China Xianhe Oil Production Plant of Shengli Oilfield Company, SINOPEC, Dongying 257000, China

鄂尔多斯盆地长7段以致密储层为主，广泛发育微、纳米级孔喉系统，孔喉连通复杂。致密砂岩储层研究的基础是精确表征这类孔喉的特征，致密砂岩储层属于非常规的范畴，采用传统的研究方法无法实现微、纳米级孔喉的精确表征。借助核磁共振技术、CT技术，具体分析了Z230井、X233井、N44井的致密岩心样品，实现了对致密储层的精确表征。核磁共振技术实验得出，可动流体饱和度是评价低渗透致密储层的一个重要参数，可动流体饱和度与孔隙度、渗透率具有相关性；T2谱图分析得出了岩样的孔隙分布特征；微、纳米CT实验得到了孔喉三维立体图，并对岩样进行扫描切片成像，直观显示了孔喉的形态特征。实验分析认为，核磁共振技术与微、纳米CT技术可以实现对致密储层的精确表征与评价，是致密储层勘探开发的一个重要的技术手段。

Chang 7 Member in Ordos Basin belongs to tight sandstone reservoir. Micrometer and nanometer pores dominate the storage space of tight sandstone reservoirs and the connectivity of pore throat system is complex. The study basis of tight sandstone reservoir is to characterize its pore and throat system precisely. The tight sandstone reservoir is unconventional reservoir and it cann′t be characterized by traditional methods． With NMR and micrometer and nanometer CT technologies and by analyzing the core samples from Well Z230, Well X233, Well N44, the tight sandstone reservoirs can be precisely characterized. It is known that mobile fluid saturation is a very important parameter in evaluating the tight sandstone reservoirs and mobile fluid saturation has correlation with porosity and permeability. By T2 spectrogram, the distribution of pore is analyzed. Through micrometer and nanometer CT test, the 3D image of pore and throat is gotten. And the scanning slice is imaged with the micrometer and nanometer CT technology. It shows the morphological characteristics of pore and throat intuitively. NMR and micrometer and nanometer CT technologies can precisely characterize and evaluate  the tight sandstone reservoirs, which are important tools for the exploration and development of tight reservoirs.

10.6056/dkyqt201501013