Article ID Journal Published Year Pages File Type
8125589 Journal of Petroleum Science and Engineering 2018 8 Pages PDF
Abstract
This paper discusses the relationship among capillary pressure (PC), nuclear magnetic transverse relaxation time (T2) and resistivity index (I). The three parameters are related to the geometry of pore structure. We use the fractal concept to describe the relationship between T2 and I.In addition, a new T2-I model is established. 8 Cores from tight sandstone reservoir in China are selected to do experiments. The results reveal that the cores have continuous fractal dimension characteristics. Additionally, the fractal dimensions appear great differences in the different pore radius scales. Therefore, a piece-wise fitting method is adopted. We divided the pores into macropore, mesopore and micropore. Through the verification, our T2-I model and piece-wise fitting method are feasible. An application example is also provided in this paper. Based on our researches, we adopt NMR logging data to obtain dynamic parameters of Archie's formula b and n for calculating water saturation in Tight Sandstone Reservoir. The comparison between our method and normal method demonstrated that our model is much better at matching the core water saturation.
Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Economic Geology
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