徐深气田火山岩储层储集空间特征及渗流机理

火山岩储层与碎屑岩和碳酸盐岩储层相比，其储集空间更复杂、非均质性更强、渗流机理尤其不清楚。为有效开发这类气田，针对松辽盆地徐深气田的特点，通过一系列大直径岩心特殊分析手段筛选，找到了适合火山岩储层特性的分析方法，从储层基本特征、渗流机理、储层敏感性评价等方面开展的实验研究，揭示出了火山岩储层储集空间特征与渗流机理。研究结果表明：火山岩储层储集空间是孔隙与裂缝的不同组合体；孔隙大小分布不均，孔隙中大孔隙被小喉道控制；储层表现出亲水特征，束缚水饱和度高，两相渗流范围小，气相渗流具有明显的低速非达西渗流特征，气相渗流存在启动压力梯度。

Reservoir space characteristics and percolation mechanism of volcanic reservoirs in Xushen gas field

Compared with clastic and carbonate reservoirs, volcanic reservoirs are characterized by complex reservoir space, strong heterogeneity and particularly the unexplained percolation mechanism. Based on the features of the studied block of volcanic reservoirs in the Xushen gas field, Songliao Basin, a suitable analysis method on volcanic reservoir properties was selected from a series of large diameter core analysis methods, and then the space characteristics and percolation mechanism of volcanic reservoirs were revealed by the experimental study in aspects of fundamental reservoir properties, percolation mechanism, and sensitivity analysis. Studies show that the space of volcanic reservoirs are the different combinations of pores and fractures; macropores are controlled by the small throat in pores resulting from the uneven distribution of pore sizes; reservoirs show hydrophilic characteristics with high irreducible water saturation and small range two phase seepage; and gas seepage has obvious characteristics of low velocity non Darcy percolation and starting pressure gradient.