核磁共振与高压压汞实验联合表征致密油储层微观孔喉分布特征

通过设计算法程序,利用压汞实验得到的致密储层孔喉分布数据,校正优化了核磁共振实验T₂弛豫时间与孔喉半径的换算系数,提高了核磁共振表征孔喉分布的精度,建立了表征致密储层微观孔隙分布特征的核磁实验方法。该方法应用于松辽盆地南部白垩系致密油样品孔喉分布表征,不同含油饱和度样品孔喉分布数据表明,含油饱和度小于10%的样品孔喉集中在10~300 nm;含油饱和度介于10%~40%的样品孔喉集中在20~1 000 nm;含油饱和度大于40%的样品孔喉集中在20~3 000 nm。致密储层中不同级别微纳米级孔隙系统的发育控制了致密油含油性。 

Characterization of micro pore throat radius distribution in tight oil reservoirs by NMR and high pressure mercury injection

Through the design of an algorithm, the conversion coefficient of NMR T₂ relaxation time and pore throat radius was optimized by using the pore throat distribution data in tight oil reservoirs obtained from mercury injection experiments. The precision of the NMR characterization of pore distribution was improved. Methods were used in the characterization of Cretaceous tight oil pore radius distribution in the southern Songliao Basin. Pore radius of samples with oil saturation less than 10% were concentrated in the 10-300 nm range, while those with oil saturation between 10% and 40% were mainly 20-1 000 nm. Unlike these samples, the pore radius of samples with oil saturation greater than 40% were concentrated in the 20-3 000 nm range.Experimental results showed that the development of different levels of microporosity in tight oil reservoirs controlled the oiliness properties.