Salt Pillows, the Mobile Substratum Controlling the Late Jurassic-Cretaceous Facies Distribution in the Hydrocarbon-Rich Province of Southeastern Mexico

Villaseñor Hernández, Javier¹, Javier J. Meneses Rocha¹, Felipe Audemard², Jorge Varela Santamaría¹, Andreas Suter², Nicolas Gonzalez Tovar¹ (1) Pemex Exploration and Production, DCS Mexico, Mexico (2) Schlumberger, Villahermosa, Tabasco

A series of evidences depicted from several reprocessed 3D surveys allow the concep­tualization of a refined model for the depositional setting of the Upper Jurassic. The differ­ences in thicknesses observed for the Kimmeridgian oolite interval appear to be induced by early salt remobilization. The oolite packages distribution are the second best reservoirs in the area and are usually deposited on top or in fault contact against shallow Oxfordian salt pillows. The pillows were leveled up at sea level and they were also the mobile substratum where the oolites were deposited on. The resulting configuration reflects several alignments of small narrow and elongated islands with a sub aquatic relief of no more than a couple hundred of meters. The differential thickness associated with these salt-rollers (pillows) gave the space for the progradation of the oolitic shoals as salt dissolved / evacuated. The Tithonian source beds were deposited next on top and reflect an inverse pattern as they developed thicker packages in the depositional lows left behind by the salt pillows and the oolitic sequence. This pattern become evident in seismic when the Middle Cretaceous mark­er was flattened. This moment is where most of the syn-sedimentary growth developed on the flank of the pillows seems to be sealed up. It is important to bear in mind that this frame­work is considerably modified by subsequent salt evacuation mainly during the Neogene due to resurgence of the Chiapas Mountains to the west.