Jurassic Hydrocarbon System Appraisal and Implications for Prospectively in Central and Southern Iraq, Middle East

Abstract

The Jurassic hydrocarbon system in Middle East is one of the world's most important systems with several giant oilfields are discovered in Abu Dhabi, Saudi Arabia, etc[1–3]. The oil and gas discoveries of Jurassic formation are located in the northern part (Fig. 1). Such as the Najmah, Atrush, and Miran West oilfield in north Iraq. Meanwhile, it also considered the main producing reservoirs big reserve in adjacent countries. However, central and southern Iraq is an underexplored area due to large burial depth and limited data. Several wells have confirmed its huge potential. The appraisal of stratigraphy sequence, sedimentation and hydrocarbon assemblages is of great significance to understand prospectively in this region. It also shed light on the exploration of Jurassic formation and deeper formations. The Jurassic contact with the lower Triassic (Kurra Chine) and upper Cretaceous (Sulaiy) in unconformity in southeastern Iraq. The contact surface often characterized by sharp lithological change[3]. For example, the Gotnia formation in top of Jurassic characterized by evaporate lithology (anhydrite and salt). However the Sulaiy formation in the bottom of Cretaceous characterized by mudstone. The Jurassic in Iraq can be further divided into lower Jurassic, middle Jurassic and upper Jurassic (Fig. 1). The lower Jurassic belongs to evaporate and carbonate ramp environment, the lithology dominated by anhydrite and dolomite. The middle Jurassic belongs to intra-shelf environment and the lithology dominated by mudstone and shale. The upper Jurassic belong to shelf and evaporate environment and the lithology dominated by mudstone and anhydrite[4–6].