t2弛豫谱在核磁共振录井解释中的应用

核磁共振录井测量过程中，t2弛豫谱是重要的参数，其中包含着孔隙度、可动流体、含油饱和度等储集层物性信息。根据t2弛豫谱分析原理着重介绍了t2弛豫谱形态在不同性质储集层中的特征，列举了油气水层的典型谱图特征：油层的谱图特征为弛豫时间较长，右半部分谱图较发育，可动流体值高、含油饱和度高；水层的谱图特征为可动流体值较高，油信号谱峰低、孔隙中以可动水为主；油水同层的谱图特征为油信号谱峰与水层相比较高，但大部分孔隙空间被可动水充填，含油饱和度一般为10％～40％；干层的谱图特征为低孔隙度、低渗透率、低可动流体、低含油饱和度。进而通过实例分析，说明了t2弛豫谱在储集层评价和油气水层解释中的重要作用。

Application of t_2 relaxation spectra in NMR logging interpretation

During NMR logging measurement, t_2 relaxation spectra are the important parameters, including reservoir physical property information, such as: porosity, movable fluid, oil-bearing saturation. According to t_2 relaxation spectra analysis principle, the author stressed the features of t_2 relaxation spectra shape in different property reservoirs and listed typical pattern feature of oil, gas and water zones. The pattern feature of oil zone was the longer relaxation time, the right half of which was more developed with high value of movable fluid and oil-bearing saturation. The pattern feature of water zone was that the movable fluid value was higher, the oil signal spectrum peak was lower and movable water was dominated in the pores. The pattern feature of oil-water zone was that the spectrum peak of oil signal was higher than that of water, but most part of pore space was filled with the movable water, the oil-bearing saturation of which was between 10%~40%. The pattern feature of dry zone was the lower porosity, permeability, movable fluid and oil-bearing saturation. The paper showed that t_2 relaxation spectra played an important role during reservoir evaluation and the interpretation of oil, gas and water zone.