裂缝-孔隙型碳酸盐岩储层孔隙度下限的求解研究

Solution of the porosity lower limit of fracture-pore pattern carbonate rock reservoir

裂缝-孔隙型碳酸盐岩储层具有复杂的孔隙结构和严重的非均质性,如何准确确定其物性下限值是目前储层研究的难题之一。作者以蜀南地区下三叠统嘉陵江组裂缝-孔隙型碳酸盐岩储层为例,选取与储层的储集能力和产能密切相关的喉道半径和含水饱和度两个参数,利用压汞和相渗透率资料,采用相关公式法求得了其孔隙度下限值,并进行了验证。结果表明,区内嘉陵江组裂缝-孔隙型碳酸盐岩储层的绝对下限为1.98%,产出下限为2.3%。这个计算结果与其他方法得到的孔隙度下限值是吻合的。

The fracture-pore pattern carbonate reservoir is characterized by the complicated pore structure and serious non-homogeneity. To accurately determine its property lower limit is one of the problems faced by reservoir researchers. By selecting two parameters closely related to reservoir capacity and productivity, that is, throat radius and water saturation, and based on the capillary pressure and phase permeability data of ;the area in study, this article takes fracture-pore pattern carbonate reservoir of the Lower Triassic Jialingjiang Formation in the south of Sichuan Basin for eample, and adopts formula method to obtain its porosity lower limit. Validation is also conducted in this article. The result indicates that the absolute lower limit of the Jialingjiang Formation is 1.98%, and its output lower limit is 2. 3%, which is consistent with the porosity lower limit derived from other methods.