Integrated Geological and Geomechanical Modeling: Its importance for cost reduction and value maximization in Pre-Salt Projects of the Mero Field, Santos Basin

Drilling wells in the Mero field has been challenging due to complex geology and critical geohazards along well trajectories. From 2015 to 2020, 12 among 40 wells were lost, and several others faced delays, resulting in increased costs and postponed production development projects. Aiming to mitigate these issues we invested in an integrated model that considered key geological and geomechanical characteristics of the post-salt, salt, and pre-salt intervals. A new interpretation of horizons and faults from the Ocean Bottom Nodes seismic data and stratigraphic correlations from well data were made, creating a framework with eight stratigraphic zones in the post-salt, modeled using techniques typically reserved for reservoir modeling. In the salt layers, facies were modeled through seismic inversion, while the pre-salt utilized the current reservoir facies model. The interpreted faults defined regions with critical mechanical properties. By analyzing the models and examining the history of analog wells, we identified geological and geomechanical risks. This approach facilitated the adjust of well trajectories to optimize operations, leading to faster, cost-effective wells, reducing drilling time by 31% and saving over USD $100 million in rig rentals from 2020 to 2023. This method is applicable to other projects facing geohazard challenges.