| The Ordovician karst caved reservoirs are the typical“residual buried-hill pools” at Lunguxi Oil Field in Tarim Basin. Three technical methods are suggested and applied to deal with problems in reservoir development. (1) Based on the analysis of karst origin, 3D seismic data are applied to interpret the hierarchical karst caves and describe development characteristics of different cave layers; (2) Oil-water interface can be determined by the karst valley trend surface to guide for preventing water in development period; (3) Based on the analysis of rock physics, the mud indicative factor is obtained, which can be used to detect the caves whether filled with mud or not, and then choose the effective reservoirs without filling by seismic inversion. By implementing above methods, the distribution characteristics of caved reservoirs are made clear in different four beds. The relationship of oil and water occurrence in caved reservoirs is clarified. It is proved that there are higher filling content in karst slope than in karst platform. Three kinds of residual oil units are evaluated. |
