储层流动孔喉下限研究

THE STUDY OF CUT-OFF PORE-THROAT IN RESERVOIR

针对传统方法中储层流动孔喉下限值的确定是以经验为主,缺乏足够的理论和实验支持的问题,根据核磁共振与常规压汞实验的相关性,将核磁共振分布转化为孔喉分布图谱,在此基础上结合离心实验建立了确定储层流动孔喉下限的理论方法。通过对大庆油田某区块砂岩、砂砾岩油藏储层流动孔喉下限计算可知,储层流动孔喉下限与渗透率之间存在良好的线性正相关性,但与孔隙度相关性较差。并在毛管模型基础上利用泊谡叶方程计算了两类岩性流动孔喉下限半径的渗透率累积贡献率值,结果表明该渗透率累积贡献率值达到99.90%,从而实现了储层流动孔喉下限的快速确定,为油田的储层评价工作提供了新的参考。

The traditional method getting the cut-off pore-throat is based on the experience,there is no enough theory and experiment to support the method.According to the relation between NMR and traditional mercury injection,the NMR map is converted into pore-throat spectrum.Combining with the spectrum and centrifugal method,a new method getting the cut-off pore-throat radius is presented.Meantime,the cut-off pore-throat radius of Daqing Oilfield is calculated.The results show there are a good positive correlation between permeability and the cut-off pore-throat radius.The porosity has little effect on the cut-off pore-throat radius.On the basis of Poisseuille formula of capillary model,the new value of cumulative contribution to the permeability,which is corresponding with the cut-off pore-throat radius,is calculated,and the results presented the value reaches 99.9%.Above study provides new reference for reservoir evaluation.