Origin of Natural Oil Seabed Seepage Along Mexican Ridges, Southwestern Gulf of Mexico: Petroleum Systems Implications and Potential

Several satellite mapping and piston core studies of oil and gas seabed seepage over the Mexican Ridges Province indicate the existence of an active petroleum system. Biomarker analysis of hydrocarbons recovered from the sea floor sediments by piston cores, indicate an aligned pattern of fluid type distribution (oil-gas) with a predominant Upper Jurassic carbonate-rich source rock affinity. On the other hand, based on regional subsurface interpretation, the potential Upper Jurassic source rocks in this region are found at depths well above the gas window. Therefore, it seems that there is no correspondence between oil shows observed on the seabed and the type of hydrocarbons that the source rocks might be expelling at present day. The objective of this work is to evaluate the petroleum system elements burial history and the thermal-pressure regimes through geological time, responsible for the timing of oil and gas expulsion and fluid migration from deep thermogenic sources. This is accomplished throughout a 2D basin modeling approach accounting for heat flow transfer, compaction-effective stress and HC fluid flow modeling through simulated geological time. The model aims to explain the origin of the type of seabed hydrocarbons seepage and the implications for the hydrocarbon potential of the Province