Abstract：Cased-hole log is logging methods finished in cased hole and aimed at solving identification of oil/gas reservoirs and computation of physical parameters in reservoirs, used in complex hole to replace bore-hole log in order to reduce logging accidents and cycle in large-slant hole. The paper introduced several common cased-hole logging techniques and their application in Zhuanghai-401 well in Dagang Oilfield. The results showed that cased-hole log could not only solve the issue of distinguishing oil/gas reservoirs, but also provide more correct physical parameters, simplify construction and shorten well-occupied cycle at the same time that is important to the offshore drilling.
