东濮凹陷二叠系有效储层主控因素及物性下限

东濮凹陷二叠系储层具有明显的低孔低渗特征，地质条件的复杂性制约了储层研究，有效储层主控因素与物性下限有待进一步确定。通过分析沉积相、成岩作用等因素对储层物性的影响，明确了有效储层发育的主控因素。沉积相直接控制了储层原始物性，河道亚相、分流河道微相及水下分流河道微相中的砂体物性较好，单层厚度大，利于储层发育，分流间湾中的砂体物性较差。成岩作用中，压实作用、胶结作用是造成储层致密化的主要作用；两次大规模溶蚀作用形成了大量溶蚀孔隙，是改善储层物性的关键因素。利用储层孔隙度、渗透率等物性资料及试油、压汞等资料，采用试油法、经验统计法及压汞参数法确定了二叠系有效储层孔隙度下限为4.8%，渗透率下限为0.04 mD。

Controlling Factors and Lower Limits of Porosity and Permeability of Permian Reservoirs in Dongpu Depression

The reservoirs of permian in Dongpu depression are characterized by lower porosity and permeability. The complexity of geological conditions restricts the research of reservoirs. Combining the analysis of sedimentary characteristics and diagenesis characteristics, the controlling factors of physical properties of Permian reservoirs were discussed．It is indicated that the sand bodies of channel, distributary and underwater distributary channel are favorable for reservoir formation because of good porosity. Diagenesis is the most critical factor affecting the reservoir porosity evolution. On the one hand, compaction and cementation are the main causes for reservoir tightness. On the other hand, dissolution is mainly shown as the corrosion of feldspars and carbonate cement, and in turn, makes the physical property of reservoirs better. Based on the porosity and permeability data of 219 samples from 26 cored wells, production test data and mercury injection data, the lower property limits of effective reservoirs were determined by oil production test method, empirical statistic method and mercury injection curve method. The results show that the lower limit of porosity is 4.8% and the lower limit of permeability is 0.04 mD.