Abstract: Shoreface and bar deposits dominate the ZH1_2L oil group of the Wenchang A field. Alternated thin layers of sand and mud are widely developed there with high clay content in the reservoir. Conventional method is not efficient in identification of the reservoir in this area. In our study, the continuous wavelet transform time-frequency spectral decomposition method was used to define the favorable reservoirs, and the results are coincident well with drilling data. Therefore, it is a reliable technical support for the oil development in this area.