Print this pageAssessing Exploratory Risk by Fault Sealing Behavior Analysis of Rift Siliciclastic Sequences Potiguar Basin, NE Brasil
In recent years, we have studied about fault sealing capabilities as the main trap mechanism in several oil fields in order to support the process of exploratory well locations as well as to minimize the risks of this kind of play. The present work represents an integrated effort of both exploratory and research teams involved in the exploratory process in the rift sequence of Potiguar Basin.
The results obtained with such a kind of studies permit to focus the exploratory efforts on those producing zones which show the highest probabilities of being controlled by fault trapping.
Microstructural analysis of fault zones identified in well cores represents the direct observation of deformation mechanisms, allowing to classify the different fault-rocks involved in the sealing process. Moreover, microstructural observations linked with petrographic analysis provide the conceptual basis to establish the relative ages between deformational and diagenetic events.
A great number of wells located in different blocks separated by faults were analyzed in one of the grabens, and the results of prediction of the fault sealing behavior simulations are in agreement with the results obtained after the well drilling. In general, the zones with higher shale/sand ratio show a potential of trapping higher hydrocarbons columns.
The good results obtained with this integrated technique have encouraged us to keep using this kind of study as a complementary tool to the process of exploration and prospect generation in the area as it seems that exploration success is intimately linked to trap integrity.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil