Abstract:

 There was no breakthrough in exploration of Chelif Basin for nearly half a century, and whether effective source rocks existed or not had become the main factors of controlling exploration. According to the geochemical analysis of samples collected from outcrop and drilling core, characteristics and distribution of Meso-Cenozoic source rock were studied and forecasted. New technology to calculate TOC value by using ΔlogR could make up for the inadequacy of samples.As a superimposed basin of Meso-Cenozoic in the northwest of Algeria, Chelif Basin, at the passive continental margin in the period of Cretaceous, was in an extentional structural environment and was a marine facies basin. Chelif Basin evolved into inter-mountain basin in the period of Cenozoic, experiencing fault sag evolutionary process, and was characterized by fast-filling depositional features. The results show that: Upper Cretaceous, Lower Miocene and Upper Miocene source rocks developed, which were moderategood source rocks according to the abundance of organic matter. Type of organic matter was II kerogen, in low mature-mature phase. Upper Cretaceous marls were the main source rocks of Chelif Basin. Hydrocarbon resources were relatively rich, and the basin was a prospective area to explore in the next step.

Key words:  Chelif Basin, Meso-Cenozoic, source rock, geochemical analysis, ΔlogR