孔喉分布约束的低渗储层渗透率定量表征方法

 低渗透储层逐渐成为海上油田开发技术攻关的重点，它的渗透率受控于孔隙结构。目前低渗透储层渗透率的定量表征主要依据孔隙度建立孔渗关系，因低渗储层孔渗关系差，所以传统方法存在计算精度低的问题。为此提出基于孔喉分布约束的渗透率定量表征方法，在表征过程中考虑孔隙结构影响，依据孔喉半径将孔隙空间划分为不同类型，通过将不同类型孔隙空间赋予不同的权值，表征不同孔喉半径对孔隙空间影响，并将各类孔隙空间加权后之和定义为各类孔喉体积综合系数。与传统方法比较，该系数与渗透率具有更好的相关性。通过在新方法中引入核磁共振测井，可实现渗透率解释结果的连续分布。应用结果表明，新方法解释渗透率具有较高精度，为低渗储层渗透率表征提供了一种切实可行的技术方法。

Quantitative Characterization of Permeability Based on the Pore and Throat Distribution Constraint

Low permeability reservoirs are becoming a focus of the offshore oilfield development technologies. The permeability can be controlled by the pore structure, and the quantitative characterization of the permeability can be established based on the relationship between the porosity and the permeability However, this kind of relationship is not very reliable, which reduces the accuracy of the permeability calculation. This paper proposes a new method of the permeability quantitative characterization based on the pore and throat distribution constraints. The pore space is divided into different types based on the size of the pore throat radius, which are given different weights to characterize the effect of the pore throat radius, and the sum of all weighted pore spaces is defined as the pore throat volume coefficient. Compared with the traditional method, the coefficient of the permeability has a better correlation. Through the introduction of the NMR logging in the new method, for a continuous distribution of the permeability interpretation, the application results show that the permeability explained by the new method enjoys a high accuracy, therefore, this method provides a viable technology for the permeability characterization of low permeability reservoirs.