Technical research of Karst cave description in fracture-cavity carbonate reservoir

As the main storage space and seepage space of petroleum in fracture _ cavity carbonate reservoir were formed between large karst cave and fracture zone,the two of which are connected,the identification and prediction of large carst cave become crucial in fracture - cavity carbonate reservoir development.Based on development pattern of paleokarst cave,in combination with structural characteristics,formation and development regularity of karst cave,starting from establishing logging identification pattern,by using geophysical and dynamic characteristics of production,the integrated identification pattern on five kinds of karst caves has been established. On the basis of development distribution regularity of karst cave system in vertical and horizontal directions, its 3D quantitative modeling was established by using quantitative modeling technique.The application in T607 - S76 of Tahe oilfield during the past 3 yeas shows that the testing result is very accorded with the reality,and the accuracy could be high up to 97%.The facts prove the 3D quantitative modeling will provide guidance and reference value for other reservoirs with the same kind.