A total of 21 core samples from well 2/7-26S of the Embla Field and One reference sample from Oseberg have been geochemically studied. In the studied well the Embla Field consists of two main reservoir units, the Upper and the Lower sandstones. Altered volcanic rocks found beneath the Lower sandstone unit. Migrated hydrocarbon is known to appear in the Embla Field.The objective of this study is to carry out geochemical analysis of the samples to characterize vertically the migrated bitumen in the Embla reservoir with the purpose of understanding the process of reservoir filling and its often complex history which are the key for source rock and oil/gas characterization. For this purpose geochemical evaluation of the Paleozoic samples have been carried out in an attempt to understand the heterogeneity of the reservoir.The geochemical analytical methods used in this study are Iatroscan TLC-FID, GC-FID and GC-MS. These techniques yielded several chromatograms and maturity and facies parameters, which are used to evaluate the geochemical heterogeneities of the reservoir vertically in terms of hydrocarbon abundance, composition, maturation, facies source and biodegradation.The two most important sections of the reservoir, the Upper and Lower sandstone are rich in hydrocarbon. However, great variations have been observed both in abundance and composition.The Embla samples are highly mature with vitrinite reflectance of more than 0.8%. The samples from the Upper and Lower sandstones show different maturity signatures. The Lower sandstone being more mature. The applicability of the biomarker based maturity is less useful for the highly mature Embla bitumen samples. Rather, aromatic hydrocarbon based maturity ratios reflect the maturity more reliably. The following maturity trend is concluded (high to low): Lower sandstone→VB →Upper sandstone→NSO-1 → Rhyolites.The bitumen in the studied well of the Embla Field are concluded to be sourced from marine algal type 2 kerogen. The bitumen from the Lower sandstones is originated partly from a more algal, restricted anoxic environment.