ABSTRACT The story of Zohr started during mid-2012 when Egyptian Natural Gas Holding Company (EGAS) launched a competitive bid round covering 15 offshore/onshore blocks in the Nile Delta. At that time, after more than 40 years of exploration, the Nile Delta plays (mostly clastic and gas prone), from the HP/HT Oligocene pre-salt to the DHI-supported Plio-Pleistocene post-salt, had all been assessed. A new innovative play was needed to restart exploration and to renew IEOC (Eni’s affiliate company in Egypt) exploration portfolio. The opportunity was offered by several blocks on auction located along the Egypt–Cyprus border in deep water/ultra-deep water, previously explored during a 12-year period (1999–2011) without commercial success. Although looking for the extension into Egypt of the multi-Tcf, biogenic gas, Levantine-style play that had been proven in 2009–2011 in both Israel and Cyprus waters by the Noble–Delek JV (Leviathan, Tamar and Aphrodite discoveries), IEOC explorers identified something profoundly different and yet similar in the Block 9 (later to become the Shorouk block). Instead of the Oligocene to Early Miocene clastic deep-water sandstones sealed by the interbedded shales in anticlinal traps, a structural high linked to the Eratosthenes Seamount crustal block showed geometries typical of a shallow-water isolated carbonate buildup, capped by Messinian salt onto which the Miocene clastics were laterally abutting. Two targets were initially inferred for the Zohr prospect, respectively Miocene and Early Cretaceous age in analogy with the sedimentary section detected by several ODP cores on the northern flank of the Eratosthenes Seamount. The Zohr-1 discovery well, drilled in 2015 in 1450 m of water, was the first well targeting a carbonate play in the East Mediterranean. It found Miocene and predominantly Early Cretaceous shallow-water carbonates facies with a 624 m continuous biogenic gas column. The following four appraisal wells confirmed the initially estimated gas-in-place volumes. Thanks to Eni Upstream Business model, driven by time to market speed and cost-effectiveness while converting discoveries into production and based on the full integration of exploration and development, only two years after the discovery the gas of Zohr came onstream (December 2017), a record for a deep-water development project. The start-up was followed by a quick and smooth ramp up, reaching even the production plateau far ahead of the plan of development commitments. In parallel, the application of Eni dual exploration model contributed to boost the cash generation from the asset. Zohr reshaped the energy scenario of the whole Eastern Mediterranean and provided the industry with a new discovered play that was quickly pursued around the Eratosthenes Seamount in Cyprus.

Abstract The vast amount of new lithostratigraphic, chemostratigraphic and geochronologic data from the Huqf Supergroup (Sultanate of Oman) has established it as the Cryogenian (850–635 Ma) and Ediacaran (635–542 Ma) reference section for the Neoproterozoic of the Middle East Region. A direct litho- and chemostratigraphic comparison of the Huqf Supergroup of Oman with the supposed time-equivalent succession of the Marwar Supergroup in western Rajasthan (India) reveals remarkable affinities in facies evolution and chemostratigraphic signature through time. Ara Group equivalent strata are also found in the Salt Range Formation of Pakistan, which shows an almost identical repetition of evaporites and carbonates with six to seven basin refreshening–desiccation cycles, comparing well with the A0–A6 Ara Group stratigraphy of the South Oman Salt Basin. These similarities bring out a consistent picture of a cratonic setting for the Marwar Supergroup of West Rajasthan, changing into a more open marine setting towards Pakistan until Oman, suggesting an assembly of Oman–Pakistan and India ‘terrains’ prior to being accreted to the Arabian shield sometime after 650 Ma. From a petroleum exploration perspective, key success factors when pursuing the Late Neoproterozoic plays in the Salt Basins of India, Pakistan and Oman are source rock maturity, charge preservation and seal integrity.

Abstract Glacial deposits are found in the Ayn Formation and Shareef Formation of the Mirbat Group close to Mirbat in Dhofar, southern Oman. The Mirbat Group is most likely a correlative of the Abu Mahara Group of the Huqf Supergroup of northern Oman. The Ayn Formation, the main subject of this chapter, comprises <400 m of mainly coarse-grained glaciogenic deposits, ponded in 2- to >8-km-wide N- to NW-oriented palaeovalleys eroded into crystalline basement, with few or no deposits preserved on intervening palaeohighs. The Shareef Formation occurs as thin, lenticular, erosional remnants beneath the unconformably overlying Cretaceous. The Ayn Formation is overlain by a thin (<3 m), discontinuous cap carbonate that passes from carbonate-cemented talus on the basin margin to stromatolitic carbonate on palaeohighs and resedimented gravity flows on palaeovalley flanks. The Ayn Formation is younger than its youngest detrital zircons and the youngest late plutons in crystalline basement, constraining it to < c . 720 Ma, but its exact age is unknown. The detrital zircon population comprises exclusively Neoproterozoic sources, suggesting derivation from the juvenile Neoproterozoic crust of the Arabian area. The composition of fine-grained matrix in glaciogenic diamictite units and of non-glacial mudstones, plotted using the chemical index of alteration (CIA), suggests strong variations in the intensity of palaeoweathering on contemporary land surfaces between the mechanical weathering-dominated Ayn Formation, and the chemical weathering-dominated overlying Arkahawl Formation, which supports the notion of major glaciation followed by rapid climatic transit as basin margins were flooded and buried with sediment during post-glacial transgression. The carbon isotopic ratio (δ 13 C) of the post-glacial carbonate is strongly variable from −3.5‰ to +5.8‰, whereas carbonate fissures in the underlying basement range between +4.1‰ and +5.7‰. Two independent palaeomagnetic studies have yielded low palaeomagnetic latitudes for the Mirbat Group.

Abstract The Abu Mahara Group ( c. 725–<645 Ma) of the Huqf Supergroup in the Jabal Akhdar of northern Oman hosts two glacial successions in the Ghubrah and Fiq formations, separated by the <50-m-thick volcanogenic Saqlah Member. The >400-m-thick Ghubrah Formation is dominated by distal glaciogenic rainout diamictites, laminites and turbiditic siltstones, whereas the <1.5-km-thick Fiq Formation exhibits a cyclical stratigraphy of proximal and distal marine glaciogenic facies, and non-glacial sediment gravity flow and shallow marine facies. The Fiq Formation is overlain by a transgressive, isotopically light carbonate known as the Hadash Formation. A tuffaceous ash interbedded with glacial diamictites of the Ghubrah Formation in Wadi Mistal has yielded a U–Pb zircon age of 713.7±0.5 Ma. The Fiq Formation contains detrital zircons as young as 645 Ma. The use of the CIA (Chemical Index of Alteration) shows the Fiq Formation to be climatically cyclic, with alternations of high and low chemical weathering of contemporary land surfaces driven by phases of glaciation and deglaciation. The transgression into the post-glacial Masirah Bay Formation is marked by a major increase in chemical weathering.