Petroleum System Evaluation for Onshore Se Abu Dhabi, through the Integration of Five Sub Surface Discipline Studies

Abstract

The assessment of a Petroleum System includes several steps, which comprise: detailed evaluation ofsource rock, charge history, trap, seal and reservoir. As a result, a multi-scale and multi-disciplinary approach was necessary to obtain a final cohesive product. This paper aimed to improve basin modelling and prospectivity evaluation thanks to the integration of structural geology analysis, geochemical analysis, petrophysical analysis, geophysical interpretation of seismic data, stratigraphic correlations and reservoir quality evaluations. An area in onshore SE Abu Dhabi was chosen for the 12-months Petroleum System Study, where fiveteams underwent rigorous technical work independently and in combination. All the analyzed data were combined to define potential leads and prospects and assess the areal risking at different stratigraphic intervals. The limitation of data availability on the eastern side of the study area, affected the confidence of the main results, but we were able to accomplish an advanced view of the risk and opportunity in the exploration for hydrocarbons within onshore SE Abu Dhabi. The Thamama F reservoir, TH_LK_3 (Lekhwair Formation), has been identified as a key explorationtarget. Thamama F is also a good regional migration carrier bed due to (1) high continuity and very good reservoir properties and, (2) it has a thick very continuous regional top seal. The Thamama B reservoir zone (TH_KH_2 – Kharaib Formation), Thamama A reservoir zone (TH_SH_1 – Shuaiba Formation) and Habshan Formation (HA_2, Sequence 3) also have good exploration potential but the POS at these intervals is relatively lower. Overall, leads in the SSE Abu Dhabi are impacted by a higher risk on hydrocarbon charge, principally due to long distance migration from the source kitchen to the north. Stratigraphic leads have been identified in the Shuaiba Formation, specifically the Upper Bab Member (TH_SH_3) and the Habshan (HA_2). They are high risk but high reward exploration opportunities, which require further work to de-risk. A detailed study of this kind has not been conducted before within onshore SE Abu Dhabi. The outcome of this extensive technical work resulting from the integration of the six distinct sub-surface disciplines and the integrated approach allow us to mature drillable prospects, which will surely be of interest for any other operating company in the same area or in different areas.