基于NMR和压汞资料的碳酸盐岩储层渗透率建模方法

A Modeling Method of Carbonate Reservoir Permeability on NMR and Mercury Injection Data

由于碳酸盐岩储层存在严重的非均质性,常用的根据孔渗关系求取储层渗透率的方式得到的渗透率与实际相差较大,不适用于现实的生产。根据碳酸盐岩渗透率的大小主要受到孔隙结构的制约,而核磁共振(NMR)的T2分布情况、压汞的毛管压力曲线和储层孔隙结构关系密切的实情,给出了基于NMR与压汞资料的渗透率模型,该模型与经典的SDR模型和Timur-Coates模型相比精度较高。通过分析中东H油田M层组121块碳酸盐岩样品的NMR和压汞资料,可以看出Swanson参数、R35、R40与储层渗透率有较好的相关关系,同时在Swanson参数、R35、R40中Swanson参数与核磁共振T2LM之间的相关性最好。因此针对压汞资料较少的问题,给出了利用NMR的T2LM计算Swanson参数,从而获得储层渗透率的方法。将该方法应用于中东H油田M井,计算获得的渗透率大小与储层的岩心渗透率大小相近,证明该方法是可靠的。

Due to the serious heterogeneity of carbonate reservoirs,the permeability obtained by the method of calculating reservoir permeability is quite different from the actual one according to the pore permeability relation.So,it is not suitable for practical production.According to the size of carbonate permeability,it is mainly restricted by pore structure,while the distribution of T2 in nuclear magnetic resonance(NMR)and capillary pressure curve of mercury injection are closely related to reservoir pore structure,a permeability model based on NMR and mercury injection data is given,which is more accurate than the classical SDR model and Timur-coates model.By analyzing NMR and mercury injection data of 121 carbonate rocks in M-formation group of H oilfield in the Middle East,Swanson parameters,R35 and R40 have a good correlation with reservoir permeability.Meanwhile,the correlation between Swanson parameters and NMR T2LM is best in Swanson parameters R35 and R40.Therefore,for the problem of less mercury intrusion data,the method of calculating the Swanson parameter by NMR T2LM to obtain the reservoir permeability is given.This method is applied to M well of H oilfield in the Middle East,and the calculated permeability is close to the core permeability of the reservoir,which proves that this method is reliable.