孔隙结构特征和非均质性对碳酸盐岩气藏开发的影响

复杂的孔隙结构是制约深层碳酸盐岩气藏高效开发的关键因素之一。为此，首先利用CT扫描技术分析了3种类型岩心的孔隙结构特征；然后，利用具有代表性的孔隙网络模型，实现了三维孔隙结构中的气相流动的可视化分析；最后，在地层条件下通过4组2块岩心串联的衰竭模拟实验研究了层内非均质对开发的影响。结果表明，渗透率主要受裂缝发育程度和分布特征、孔隙连通性影响；在连通性弱的孔隙结构中，气相流动的连续性较差，气相流速和渗透率较低。数量小于30%的大孔隙和孔洞的存在大幅提高了储层的孔隙度。在碳酸盐岩气藏开发中，考虑层内非均质性对气藏开发的影响，应依据不同孔隙结构中的气相流动特征选择合理的生产方式促进气藏在水平方向的协调开发。

The influence of pore structure and heterogeneity on development of carbonate gas reservoir

The complex pore structure of deep carbonate gas reservoir is one of the key factors affecting the efficient development of deep carbonate gas reservoir. Firstly， the pore structure characteristics of three types of cores were analyzed by CT scanning. Secondly， using representative pore network models realized the visualization analysis of gas flow in 3D pore structure. Finally， the influence of horizontal heterogeneity on development was studied by the depletion development experiments of two cores in series under reservoir conditions. The results showed that the permeability was mainly affected by fractures characteristics and connected pores； in the pore structure with weak connectivity， the continuity of gas flow was weak， so the gas flow velocity and permeability were low. The existence of large pores and holes with a quantity of less than 30% greatly improved the porosity of the reservoir. In the development of carbonate gas reservoir considering the influence of horizontal heterogeneity， it is necessary to choose a reasonable production mode to promote the coordinated development in the horizontal direction according to gas flow characteristics in different pore structures.