Solution of high velocity anomalies imperceptible to the seismic resolution, by means of synthetic models, Penobscot Field, Canada

• Main Authors: García, Wilmer Emilio, Galeano, Iván Daniel Omaña
• Format: Article in Journal/Newspaper
• Language: English
• Published: Faculty of Mining, Geology and Petroleum Engineering 2018
• Subjects: High Velocity Anomaly; Mississauga Formation; Nova Scotia; Canada; Lower and Upper Cretaceous; Ray Tracing; Kirchhoff PSTM and PSDM; naskapi
• Online Access: https://hrcak.srce.hr/ojs/index.php/rgn/article/view/7326

Penobscot Field is located in the Sable Sub-basin in Nova Scotia, Canada, where a 3D seismic acquisition campaign was carried out in 1991 and also two oil wells were previously drilled (L-30 and B-41). In the interpreted seismic data, a dis- crepancy was found in the travel times of the seismic waves near well B-41, causing a false structural height in the Naskapi Member, Mississauga Formation (Early Cretaceous or Lower Cretaceous) and deeper formations (10 to 15 ms, i.e. approximately 25 m). It was decided to find a solution of this problem using synthetic models. First, making a delimita- tion of the study area by means of a seismic subcube, which were later interpreted surfaces of interest, through the well data. The average velocity and density properties were found for each interpreted strata. Subsequently, a 2D seismic acquisition was simulated, choosing a line that crossed both wells and through the use of ray traces, synthetic shot gathers were obtained and processed through the use of different seismic migration tests, and the final solution was found to be Kirchhoff pre-stacking migration in depth.