基于高压压汞技术的致密储层有效孔喉半径下限及影响因素

Lower Limit of Effective Pore Throat Radius of Tight Reservoir Based on High Pressure Mercury Injection Technology and its Influencing Factors

以低渗储层样品为研究对象,利用高压压汞方法对致密储层有效孔喉半径下限其进行研究。确定有效孔喉半径下限,并对其在致密储层中的影响因素进行了探讨。研究发现,有效孔喉半径下限与孔隙度关联性不大,并非一个定值,而是随着渗透率的增大而增大。平均喉道半径越大,最大连通喉道半径越大,则有效孔喉半径下限也越大。且其与平均喉道半径的相关性(R_(1)=0.7064)好于与最大连通喉道半径的相关性(R_(2)=0.6596)。在喉道参数方面,分选系数Sp越大(分选性越差),变异系数C越大,均质系数越大,结构系数越大,有效孔喉半径下限提高。

In view of the fact that predecessors seldom used high-pressure mercury injection technology to study the lower limit of effective pore throat radius of tight reservoir,39 samples were studied by high-pressure mercury injection method. The lower limit of effective pore throat radius is determined,and its influencing factors in tight reservoir are discussed. It is found that the lower limit of effective pore throat radius has little correlation with porosity,which is not a fixed value,but increases with the increase of permeability. The larger the average throat radius and the largest connected throat radius,the greater the lower limit of effective pore throat radius. And its correlation with the average throat radius( R_(1)= 0. 706 4) is better than that with the maximum connected throat radius( R_(2)= 0. 6596). In terms of throat parameters,the greater the sorting coefficient sp( the worse the sorting),the greater the coefficient of variation C,the greater the homogenization coefficient,the greater the structure coefficient,and the lower limit of effective pore throat radius is improved.