Tectonic Influence In Trap Generation During The Early Eocene, Talara Forearc Basin, Nw Perú: A Case Study Of The Mogollón Formation

The Mogollon Formation represents one of the most important productive reservoir in the Lower Eocene of the Talara basin, northwest Peru, having accumulated almost 300 millions barrels since 1910. From a sedimentological point of view, transgressive deltas, alluvial fans, deltas and braided fluvial systems are interpreted from base to top. A complete geological overview was carried out, targeting the evaluation of the development and exploratory potential of blocks X and XVI. Well data, integrated in regional cross sections, were the base of the interpretations. The integration of production and seismic data has allowed, in some areas, the calibration of the interpretation based on electrical logs. A complex fault interation is observed, which gives some indication of how the trapping mechanism has evolved during periods of high and low tectonic activity. Basically we interpret two main traps styles: a) sand-conglomerate bodies which were subsequently tilted by tectonic activity, and where the hydrocarbon potential is higher in positions close to the back of master faults, and b) where regional listric faults have triggered rotational features (rollovers) in the hanging wall, increasing the frequency of small subordinate faults located at or near the top of the deformed structure. Consequently, productivity increases due to an improvement in the original reservoir permeability. In both cases, the final recovery is better than in other situations as for instance, in wells drilled on the flanks of rollover structures.