The Application Study Of NMR Logging

This topic takes the nuclear magnetic resonance (NMR) logging principle as foundation, takes the Hers1.0software as the backing, unifies the NMR laboratory experiment, establishes reservoir Parameter Porosity, the Permeability and saturation explanation model by the NMR logging. According to mercury injection experiment data and NMR experimental data of low permeability reservoir in the HuaQing area, through method of the two-dimensional area, fitting of T2geometric mean, three-porosity three kinds of method for the evaluation of reservoir pore structure. In combination with the capillary pressure curve shape, contrast of pore diameter frequency distribution and T2distribution, comparing the logging data processing and data of testing oil the three kinds of method to build the classification of low porosity and low permeability reservoir in the HuaQing area, and then treat the wells of HuaQing region with the classification criteria, we can delineation of reservoir accurately by application pore structure parameters. It has important direct sense for researching movable resource evaluation with low porosity, low permeability and tight reservoir and developing this kind of reservoir in the Oilfield on western China.With the breakthrough improvement of reservoir pore structure of the evaluation method by the NMR logging data, but there are many methods are influenced by hydrocarbon in reservoirs which make the calculating of the pore structure parameter errors too large. This article through compared with fake capillary pressure curve calculation error of the pore structure parameters and oil saturation curve in the hydrocarbon filled reservoir, found that oil saturation can effectively eliminate the influence of the hydrocarbon in reservoirs. And compared with the method of geometric mean of T2fitting and fake capillary pressure curve transformation method which after eliminate influence of the reservoir of hydrocarbon, can find two methods have good consistency. Both methods can high precision and successive characterize reservoir pore structure, therefore it can be used for practical production.The most important parameter is the cutoff values of T2when NMR T2spectrum distinguish the movable fluid and bound fluid, the T2cutoff value can be determined mainly by the laboratory, and different blocks, different layers or different lithology’s T2cutoff values has greatly difference. For example, T2cutoff value is in the1-40ms in low porosity, low permeability and tight reservoir, and the calculation error will be very big as T2cutoff value has such a wide range distribution. According to core NMR experiment to get the T2spectrum shape and analysis for other magnetic parameters in the Sulige area, looking for the relationship between T2cutoff value and the morphology of T2spectra, and use key parameters of NML fitting with T2cutoff values to find their relationship, eventually determine the method of gain applicable T2cutoff value for dynamic calculation of reservoir. Increase the calculation reservoir permeability, moving fluid porosity precision.There are abundant heavy oil resource in major oil fields of China and the rest of the world. Recognition and evaluation of NMR of Heavy oil is still in the exploratory stage in the world, as the T2distribution signal and bound water signal are overlapping for heavy oil, the methods of low viscosity crude oil NMR evaluation cannot be applied to the evaluation of heavy oil. This paper summarizes the reason and law of low resistivity reservoir in the Xinli-Xinbei region, with the analysis of the viscosity of crude oil though NMR experiments, summarizes the heavy oil’s characteristics of different viscosity at different echo interval and different waiting time. And use various methods such as the T2distribution shape, the rendezvous of resistivity and moving porosity, shift spectral distribution, contrast of T2geometric mean, difference spectrum of shift spectral and differential spectrum and so on to multiple analysis for comprehensive evaluation of the characteristics of heavy oil in the Xinbei-Xinbei region. We made a new processing and interpretation for the Magnetic materials in the Xinli-Xinbei region with the NML heavy oil processing module which development by this research, the coincidence rate reached91.3%.