恒速压汞技术在气田储层孔隙结构研究中的应用

Application of constant-rate mercury injection technology in reservoir pore structure study of Sulige Gas Field

李珊 孙卫 王力 马永平

西北大学地质学系大陆动力学国家重点实验室，陕西 西安 710069

State Key Laboratory of Department of Geology/Continental Dynamics, Northwest University, Xi′an 710069, China

以恒速压汞实验为基础，从喉道、孔隙、孔喉半径比及毛细管压力曲线变化特征4个方面，对苏里格气田苏48—苏120区块储层微观孔隙结构进行分析。结果表明：渗透率越大，峰值喉道半径及主流喉道半径越大，喉道半径分布范围越宽，大喉道越多；微观孔隙结构越好，孔喉半径比分布范围越窄，平均值越小，驱油效果越好；低渗透储层不同渗透率样品孔隙半径差异不大，微观孔隙结构的差异主要体现在喉道的大小和分布上，喉道是影响储层渗流能力和开发效果的关键因素。

Based on the result of constant-rate mercury injection experiment, the reservoir mircro-pore structure of Block Su 48 and Su 120 in Sulige Gas Field was evaluated quantitatively from the direction of throat, pore, pore-throat ratio and capillary pressure curves. The result shows that the greater the permeability is, the bigger the peak throat radius is, the wider the distribution of the throat radius is and the more the big throat is. The better the micro-pore structure is, the narrower distribution the pore-throat ratio is and the smaller its mean value is. The pore radius of different permeability samples in low permeability reservoir is similar and the differences of pore throat are mainly the size and distribution of throats. Throat is the determinative factor to control the percolation ability and development effect of low permeability reservoir.

10.6056/dkyqt201304019