缝洞型凝析气藏衰竭开采动态实验研究　　

Dynamic experiment study on depletion development of condensategas reservoir with fracture and cave

郭平 王娟 刘伟 杜建芬 汪周华

GUO Ping WANG Juan LIU Wei DU Jianfen WANG Zhouhua

油气藏地质及开发工程国家重点实验室·西南石油大学，四川成都　610500 中国石油玉门油田分公司，甘肃酒泉　735000

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Yumen Oilfield Branch of CNPC, Jiuquan 735000, China

缝洞型碳酸盐岩凝析气藏作为目前的非常规气藏之一，具有储集空间类型多样化、埋藏深、构造复杂、储层非均质性极强、连通性差、各储集体间天然能量差异大的特点，其储层的双重介质属性决定了油气在储层中渗流的特殊性，而凝析气在多孔介质中的复杂相态特征也进一步增加了该类气藏高效开发的难度。从研究衰竭开发动态的角度出发，采用人工造洞造缝制成的缝洞型碳酸盐岩全直径岩心对富含凝析油的凝析气进行了不同介质、不同倍水体、不同开采速度及缝洞不同连通方式多种情况下的衰竭实验研究。研究结果表明：多孔介质存在有助于凝析油采出，缝洞不同连通方式时，凝析油采出程度为顶部连通小于水平连通，水平连通小于底部连通；水体存在有助于凝析油采出，水体越大凝析油采出程度越大，不同衰竭速度对凝析油采出程度的影响不大；岩心填砂后，由于砂砾产生的多孔介质界面影响及阻挡作用，凝析油采出程度高于未填砂时。该研究成果对指导缝洞型凝析气具有一定的指导意义。

As one of the unconventional gas reservoirs nowadays, carbonate condensate gas reservoir with fracture and cave has the characteristics of diverse pore types, deep bury, complex structure, strong reservoir heterogeneity, weak connectivity and great difference in natural energy distributed in each reservoir space. The particularity of condensate gas flowing in carbonate reservoirs is determined by the double medium reservoir properties; meanwhile, the complex phase characteristics of condensate gas in porous media further increases the difficulty of these reservoirs efficient development. Starting from the point of view of dynamic depletion development, the depletion tests have been done under different conditions such as different media, different size of aquifer, depletion rate and the connective type of fracture and cave, by using oil -rich condensate gas tested in artificial full diameter fracture-cave carbonate core. The results demonstrate that porous media has contributed to the condensate oil recovery; the recovery percent of reserves in cores with different connective type of fracture and cave is different, and the sequence as followed that connecting at the top is smallest, connecting at the bottom is largest and connecting at horizon is in the middle; the presence of aquifer is helpful for oil recovery, and the larger the aquifer size, the higher the oil recovery; the depletion rate has little effect on oil recovery; the oil recovery could be higher if the cave in the cores is filled by sand, since the porous media interface influence and resist effect caused by gravel. The study result Has certain guiding significance for developing the carbonate condensate gas reservoir with fracture and cave.