Conventional seismic attributes often provide satisfactory results, especially in the characterization of conventional reservoirs such as sandstones. This is not so evident with more compact, low-permeability, and apparently uniform reservoirs, which comprise substantial reserves in amounts unthinkable a few decades ago, and whose development seemed almost impossible until very recently. Unconventional reservoirs considered in this article are located in a predominantly Jurassic-Cretaceous rifted depositional basin. The basin shifted into an early sag phase during the late Jurassic and early Cretaceous, resulting in the accumulation of a thick series of carbonates and shales. Tithonian, Berriasian and Valanginian rocks compose the segment of the geologic column under consideration. The studied sedimentary sequence is a highly prolific oil-prone source rock, with total organic carbon (TOC) up to 8 wt% and amorphous organic matter (type I/II kerogen) deposited in a euxinic paleoenvironment which generated sulfur-rich oils.