Biostratigraphy of Upper Jurassic Plays in Unconventional Reservoirs in Mexico

The generation of well calibrated biostratigraphic columns establishes the best delimitations by ages and paleoenvironment, as well as the patterns that represent the deposition history.

The middle Tithonian of the analyzed wells represents the best potential interval to be proposed in a unconventional reservoir, due to the fact that it showed a high content of micro fossils, organic material and oil impregnation. This interval noted peaks of micro fossils abundance, mainly conformed by the group of radiolaria (espumelarids and neoseralids), stomiospheroids and microcriniods (Soccocoma arachnoidea). Besides, at this type of Play, maximum flooding surfaces have been logged favoring deposits of sediments rich in total organic carbon and consequently formation of source rocks.

The proposed bio zones for the navigation of the horizontal wells are the Chitinoidella and Saccocoma-radiolary biozones, in areas of paleobatimetry of external ramp distal to basin.