Seismic Stratigraphy of Cenozoic Deposits in Salaverry Forearc Basin, Peru: New Insights in Assessing Potential Reservoirs and Plays

Abstract

Abstract

This work is focused in Salaverry Basin, Peruvian Andes Forearc, which contains three oil seeps sampled and analyzed, suggesting at least one active petroleum system inside the basin. Seismic stratigraphic analysis calibrated with available well and core data, and integrated with Apatite fission track (AFT) analysis was performed in order to provide the spatial-temporal evolution of Cenozoic depositional systems in this basin. It has been developed in extensional tectonic setting punctuated by compressive periods controlled by the interaction between Nazca and South American plates, and Nazca ridge subduction. As a result, the Cenozoic succession in the central portion of Salaverry Basin is best subdivided into eleven seismic stratigraphic sequences: 3 second-order sequences (S1, S2 and S5) and 8 third-order sequences (S3, S4, S6–S11), controlled predominantly by tectonism and also by sea-level fluctuations. Indeed, this work adds new potential reservoir rocks in the S1, S2, S4, S5, S7 and S8 sequences; and seal rocks in the S3, S6, S7 and S9–S11 ones for the petroleum systems previously defined in the basin: Upper Jurassic Chicama – Cenozoic (.) and Albian La Zorra – Cenozoic (.). Fission track thermochronology analysis on apatite suggest a main uplift event in the basin at ca. 25 Ma, which triggered the erosion of Oligocene rocks and the uppermost section of the Upper Eocene deposits, and is correlated with the Incaic III Andean tectonic phase. These new petroleum system elements are related to the potential plays proposed in this work, which in turn through a follow-up assessment would become in very attractive exploratory prospects located in Salaverry Basin central portion.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016