Modelagem de Dados Magnetotelúricos na Parte Emersa da Bacia Potiguar, Brasil

The geophysics has several tools for exploring the subsurface; the most used techniques are related to the propagation of acoustic waves, such as seismic reflection. However, imaging under certain geological features with compositional heterogeneity or high velocities is a hard task to interpreters and have to be carefully treated during seismic processing. Thus, alternative methods can be applied to solve problems caused by seismic reflections masked or ignored. The magnetotellurics method (MT) uses measurements of the electric and magnetic fields on the terrain surface to estimate the distribution of resistivity in the subsurface. Whereas layers that typically cause problems for seismic (basalts, carbonates and salt bodies) have resistivities higher than in adjacent sediments, this method is able to define both the top and base of these features. So, this method can be used as a tool to help and improve seismic geophysical exploration of the Earth. The Potiguar basin (Brazil) is strategically important in the composition of energy resources of Brazil. This basin is considered semi-mature, however, some alternatives have been applied to maintain or increase production of oil and gas. Most of the exploratory effort in Potiguar Basin applies seismic techniques to study the geology of the subsurface. However, Potiguar has a shallow carbonate layer that often masks some geological features in the seismic imaging. The main purpose of this study is to analyze the magnetotellurics method in Potiguar Basin. To this goal, we simulated four situations in this basin based in geological information. The results can be used both to evaluate the method in sedimentary basin with the same characteristics as Potiguar basin, how to design configurations of possible acquisitions of MT data in the area.