Experience Study of Accurate Thin Layer Reservoir Prediction - Key Steps to Improve Pre-stack Inversion Result

Pre-stack inversion is not a new method to do reservoir prediction, however，there are still a wide space of studying how to use it to achieve more reliable and useful result for exploration. Thin sand reservoir existence in sand-shale inter-bed group is a favourable hydrocarbon bearing system and exploration target in the world. But in the limited of seismic resolution, how to combine geological and geophysical information properly to get reliable and accurate thin layer prediction result with relative higher resolution is a foremost issue during doing EI inversion. As a typical sand-shale thin inter-bed reservoir, a high resolution pre-stack inversion was engaged in Pañacocha oil field of Oriente basin, Ecuador, to understand the reservoir distribution, detect the thickness and lateral variety. Based on successful experiences, several key steps and parameter optimization principle are summarized and applied to M2 sand reservoir prediction in this research. An extremely match prediction result with blind check well proved it helps to improved accuracy of prediction grandly. The major aspect of this paper is to discuss these key steps and how to apply them properly.