Study on the Application of the EPSTM Image based Post-stack Spectrum Imaging to the Identification of the Riverway Sand Bodies in Fuyang Oil Layer of Songliao Basin

摘要

The later-period structure of Fuyang oil layer is complex and its reservoir is mostly composed by the sand bodies of riverways. The oil and gas reservoir features obvious concealment, and also is difficult to identify. To accurately describe the reservoir, a post-stack spectrum imaging was made for the identification of the riverway sand bodies in Fuyang oil layer using EPS image in the study area. The statistical error of the riverway sand body identification result using post-stack spectrum imaging was small if the sandstone thickness was greater than 3 m. Seen from logging well's geological verification, the riverway identification fit rate was 81.6% on average, the microfacies type identification fit rate was 75%, and the microfacies types identification fit rate of the sandstone thicker than 3 m was 80%. Using the nonlinear algorithm of the MDI software, the lithologic prediction was implemented based on the sand group as the unit, and the average prediction fit rate of the sandstone thicker than 3 m reached 90% according to the standard relative error less than 20%. Therefore, the post-stack spectrum imaging can exert a significant effect for the anisotropic reservoirs of complex later-period structure, thin sand body, and complex changes, and can meet the needs of the oil field exploration and development to some extent.