Jurassic Petroleum System in the Polish Lowlands (Central Poland) - Organic Geochemical and Numerical Modelling Approach

Abstract

The study area comprising the cantral part of the Polish Lowlands, termed Mogilno-Łodź Synclinorium. This area could be important petroleum exploration target in Poland, especially for unconventional resources. In this paper, we evaluate organic source facies and the results of basin modelling in order to improve understanding of the regional petroleum system. Geochemical and petrographic analyses of potential source rocks were used in this study. Our investigations showed that the organic carbon contents is high – up to 7.5% wt% in the Upper Jurassic and even to 5.5 wt% in the Middle Jurassic strata. with nearly 50 mg of hydrocarbons/g rock. A large majority of the study area source rocks reached initial and main phase of „oil window”. Numerical modelling of generation of hydrocarbons indicates the source rocks entered the early mature phase in the early Cretaceous time, and mian phase of “oil window” in the late Cretaceous time. The generation was terminated as a result of post-Cretaceous inversion of the study area. The Jurassic source rocks do not show expulsion. The pore spaces are saturated by hydrocarbons generated, indicating possible presence of unconventional hydrocarbons accumulation in the analyzed rocks.