Division methods of connectivity units of reef beach carbonate reservoirs in Tazhong I gas field

The fractured-vuggy system of Ordovician platform margin reef beach reservoirs in Tazhong I gas field is composed of hole, hole and fracture in space. In view of the complexity of the fractured-vuggy system of reef beach reservoirs, this paper puts forward the research ideas and methods of dynamic and static analysis of the fractured-vuggy connectivity of reservoir. ①Sedimentary facies, reservoir development horizons and depths are similar in the same fractured-vuggy unit. ②Formation pressure analysis is the most simple and straightforward methodology, which is the necessary and sufficient condition of connectivity study. ③The difference of fluid properties of the same fracture cavity element is small. If the difference of fluid properties is large, it cannot be connected, and the reverse recursion does not work. ④Inter-well interference test can accurately analyze the dynamic connectivity, which is the necessary and sufficient condition of connectivity study. ⑤Production dynamic data can be used to assist connectivity unit division. Through the study of static and dynamic data, the TazhongⅠ gas field is divided into 53 connected units, of which there are 3 connected fractured-vuggy systems distributed along the platform margin.