1D modelling of the NW Sab'atayn Basin Upper Jurassic source rocks, Yemen: Implications for hydrocarbon generation and thermal maturity

Abstract

Sab'atayn Basin is considered to be the most petroliferous Mesozoic basin in Yemen, although exploration efforts in the northwestern part of the basin are unproven due to scant drilling activities. In this work one‐dimensional (1D) basin modelling was used to examine the hydrocarbon generation and expulsion history of the Upper Jurassic source rocks using PetroMod2012.2 software. The geo‐history modelling was applied for the studied wells, and it shows that some stratigraphic units are missing, which adversely affect the tectonics, sedimentary subsidence, burial history, hydrocarbon maturation, and generation. There is a major period of subsidence that occurred in the Upper Jurassic and is manifest in the Kamaran‐01 well. In addition, a second major uplift occurred in the Miocene and had a discernible effect on heat flow distribution as well as burial histories. Reverse heat flow is observed in the Saba‐01 well, where the present heat flow is greater than the palaeo‐heat flow. The beginning of petroleum generation in the Meem and Lam members (Madbi Formation) source units has been predicted to occur during the Late Jurassic, and subsequently occurred in the Lower Cretaceous. Peak expulsion of hydrocarbons from the Meem Member occurred in the Eocene and late Oligocene, while expulsion modelling performed on the Lam Member asserts that it has not reached the phase of oil expulsion.