The reservoir characteristics and their significance for deliverability in metamorphic granite buried hill: a case study from the JZS oil field in the Liaodong Bay Basin, NE China

Abstract

The previous studies show that the fractures are the main reservoir space of metamorphic rocks. But the oil and gas production capacity of the fracture segment is obviously different in JZS oil field. Demarcating the reservoir zones finely and finding the high quality seepage of reservoirs are the keys to explore and develop the metamorphic rock oil field efficiently. Based on the data of cores, thin section, physical property, conventional logging, imaging logging, and production logging, the reservoir types and their logging response characteristics of the JZS oil field in Liaodong Bay Basin were analyzed, and the differences in capacity of different zones of reservoirs are discussed. The results show that (1) the reservoir of the study area can be divided into weathering crust zone, natural fractures zone, and structural breccia zone, and different reservoirs have different logging response characteristics; (2) the weathering crust zone and the structural breccia zone are the main effective seepage reservoirs, and the seepage capacity of the fractured reservoir is greatly changed; and (3) the reservoir type, fracture density, and the relationship between fracture and that of maximum principal stress control the deliverability difference of the metamorphic rock reservoir.