砂岩储层的毛管压力曲线反演模型

INVERSE MODEL OF CAPILLARY PRESSURE CURVE FOR SANDSTONE RESERVOIR ROCKS

储层孔喉分布是储层评价的重要研究内容。储层孔隙度和渗透率是储层微观孔隙结构特征的宏观综合表现。通过对来自吐哈、辽河、胜利和四川德阳等地区油气田 393个砂岩样品压汞测试资料及物性数据的多元统计分析研究 ,成功地发现了对于砂岩储层 ,孔隙度和渗透率 (特别是渗透率 )与岩样不同孔喉大小的体积分布有密切的相关性 ,建立了毛管压力曲线反演模型 ,即储层孔喉体积分布预测模型 ,解决了在一个地区部分层段、部分井因缺乏压汞测试样品或岩芯资料给储层孔隙结构研究带来的困难 。

The pore throat size distribution of reservoir rock is an important parameter used in reservoir evaluation. The porosity and permeability of reservoir are synthetically macroscopic reflection of microscopic reservoir pore structure characteristics. Through analyses of mercury injection data and poroperm data of 393 sandstone samples collected from Tuha, Liaohe, Shengli and Sichuan oil and gas fields in China, it is found that for sandstone reservoir rocks there exists a close relationship between porosity and permeability (especially permeability) and pore volume distribution by characteristic throat sizes. Based on this realization, inverse models of capillary pressure curve, i.e. the predictive model of reservoir pore throat distribution, are established. These models can solve the problem encountered in the study of reservoir pore structure where that is a shortage of mercury injection data or core samples for some layers or some wells of an area. Also, these models can help correctly evaluate heterogeneity of reservoir pore structure.