Cascade and Chinook are milestones in the development of ultradeepwater assets in the Gulf of Mexico, where the industry's experience in Lower Tertiary, Wilcox trend reservoirs is still very limited. Factors such as reservoir compaction, the production of sand, the reactivation of fractures, and other geomechanical processes affect the quality of the reservoir and integrity of the wells. To help evaluate these risks, Petrobras and the Schlumberger team built a comprehensive 4D geomechanical model and selected a unique combination of tools to reduce risk and rig time on Cascade and Chinook.