碳酸盐岩储层孔隙结构的影响因素与储层参数的定量评价

近几年，在海外区块遇到了大量的孔隙型碳酸盐岩储层。由于岩性复杂，孔隙类型多样，致使其孔隙结构十分复杂，储层参数难以准确计算，油气储量难以客观评价。文中针对研究靶区这一类型的碳酸盐岩储层，首先从沉积作用和成岩作用两个方面分析了孔隙结构的影响因素，得出在不同岩性之间，孔隙类型之间的差异是造成孔隙结构存在较大差异的主要原因。而在同种岩性之间，泥质含量的增加会降低孔隙结构的品质。另外，成岩作用对颗粒粒径较大的岩石的影响更大一些。其次，讨论了储层参数的定量评价，由于不同类型孔隙的共存，导致孔隙度相似，而渗透率、饱和度等储层参数却存在较大差异。针对这一问题，指出了可以采用核磁和成像等特殊测井资料来表征不同类型孔隙的数值分布，利用三维数字化成像技术来展示不同类型孔隙的空间分布，为储层参数的准确计算和油气储量的客观评价奠定基础。

Influential factors of pore structure and quantitative evaluation of reservoir parameters in carbonate reservoirs

In recent years, a large number of porous carbonate reservoirs have been explored and developed in overseas blocks. Due to the complex lithologies and pore types, the pore structure is very complicated. Therefore, it is difficult to accurately calculate the reservoir parameters and evaluate oil and gas reserves. In order to accurately evaluate carbonate reservoirs, firstly, the influential factors of pore structure are analyzed based on the deposition and the diagenesis. As a result, in different lithologies, the difference between pore types is the main reason for a large difference between pore structures. In the same lithology, the increase in clay content can reduce the quality of pore structure. In addition, the diagenesis has a large impact on the rock with the larger particle size. Secondly, the quantitative evaluation of reservoir parameters is discussed. Due to the coexistence of different types of pore, the reservoir parameters including the permeability and the saturation are quite different while the porosity is similar. In order to solve this problem, the NMR and imaging logging data can be applied to characterizing the numerical distribution of different pore types. Additionally, the three-dimensional imaging technique can be used to show the spatial distribution of different pore types. This study laid a foundation for the accurate calculation of reservoir parameters and objective evaluation of oil and gas reserves.