Improvement of petroleum exploration success in geological basins can be achieved by better understanding of their petroleum systems. This study covers several fields in NW Oman which contain oils from four of Oman’s petroleum systems, the Q, Cambrian/Pre-Cambrian Huqf, Jurassic ‘Tuwaiq’ and Cretaceous Natih (cf. Grantham et al., 1987). The aim of the study is to produce a better understanding of the geochemical character of all four petroleum systems, focusing on the Natih and Tuwaiq systems, as most reservoired oils in the area are thought to be mixtures. Earlier studies have stated that pure Natih and Tuwaiq oils and source rocks can be distinguished geochemically (Terken, 1999; Terken et al., 2001). However, their relative contributions are uncertain within mixed oil accumulations, especially when input from one is minor compared to the others and where some reservoirs contain indigenous as well as migrated hydrocarbons. This creates a need for a detailed study using both free biomarkers and biomarkers bound to kerogen. Results obtained suggest diagnostic molecular markers and their distributions can help in determining the contribution of hydrocarbons from these source rocks (SR) in various oil accumulations. This will also help in mapping out the oil families in North West Oman, their quality variations and the controls behind them.

Improvement of petroleum exploration success in geological basins can be achieved by better understanding of their petroleum systems. This study covers several fields in NW Oman which contain oils from four of Oman’s petroleum systems, the Q, Cambrian/Pre-Cambrian Huqf, Jurassic ‘Tuwaiq’ and Cr...