Thermal history of the Sabinas - Piedras Negras Basin (Northeastern Mexico): Insights from 1D modelling

International audienceThe thermal and burial history of the Sabinas-Piedras Negras basin was studied by 1D modelling using vitrinite reflectance values measured on core samples from nine wells. Three heat flow scenarios led to model calibrations, including a simple one and a complex one integrating a thermal anomaly following the maximal burial phase. The differences in hydrocarbon generation curves due to these two scenarios were studied. The studied thermal anomaly induces two distinct phases of primary cracking of kerogen. The first phase is clearly due to burial, whereas the second seems to be due to the thermal event. The increase in the proportion of converted organic matter attributed to this second phase varies depending on the source rocks considered, e.g., for the La Casita source rock, there is a 10% TR increase, whereas that of the La Peña and Eagle Ford source rocks, is 35 and 15% respectively. The thermal evolution of organic matter in the Sabinas-Piedras Negras Basin is mainly due to the burial phase. In contrast, the thermal event considered only causes a temporal shift of hydrocarbon generation. This hydrocarbon generation, primordially gas, occurred mainly before and during the compressive phase ("late Laramide" time step 40-35 Ma [middle-late Eocene]) that affected the Sabinas-Piedras Negras Basin