Тип бассейна:
Подтип бассейна:
Класс бассейна:
Возраст бассейна:
Тип полезных ископаемых:
Геологический возраст начало:
Геологический возраст конец:
Площадь: 152605.3 км²
Levant Basin
The Eastern Mediterranean Levant Basin is emerging as a major petroleum province due to the discovery of more than 70 TCF of proven natural gas reserves between 2006 and 2015; fields include Tamar, Leviathan, Aphrodite and Zohr. Lebanon, part of the greater Levant region, is located on the active NW margin of the Arabian plate, the margin being largely defined by the left-lateral Levant Fracture System. To the east is the petroliferous Palmyride fold-and-thrust belt and to the west the stable foreland of the Levant Basin. Onshore, in Syria, recoverable reserves are estimated at about 2.5 billion (B) brl of oil and about 8.5 TCF of gas, with fields located in the Palmyrides, the Euphrates graben, and the Sinjar high. Therefore, Lebanon and the adjacent offshore are considered to have significant exploration potential.
In the last decade, the East Mediterranean Levant Basin has become a frontier hydrocarbon province. Several gas discoveries have been recorded in Miocene reservoirs offshore Israel, and seismic data suggest promising prospective plays in deeper intervals throughout the basin. Source rock quality, quantity, and distribution as well as thermal history are hitherto not well constrained, especially in the deep offshore.
Several potential petroleum systems have been suggested, including an Upper Cretaceous–Oligo-Miocene biogenic and thermogenic system in the deep basin, a Jurassic–Cretaceous system along the margin, and a Permian–Triassic system in the onshore. Sensitivity analysis in the poorly calibrated offshore basin showed a large uncertainty with respect to the depth of the oil and gas window and suggested an important effect of the depth of the lithospheric–asthenospheric boundary on the thermal history of the basin. The different scenarios showed that the thickness of the biogenic zone below the Messinian salt would vary between 700 and 1500 m in the deep basin offshore Lebanon.
The growing global demand for oil, natural gas, and other sources of energy has moved exploration to challenging and complex provinces. The East Mediterranean region is one of those frontier provinces. Recent gas discoveries in Oligocene and Miocene sandstone reservoirs offshore Israel and Cyprus (e.g. Zohr, Tamar, Dalit, Leviathan, Karish, Tanin, Dolphin, and Cyprus-A) (www.nobleenergyinc.com; Esestime et al. 2016) have proven the hydrocarbon potential of the Levant Basin. The source of this gas is still unclear, although it has been reported to be of biogenic origin comprising 99 % methane (Needham et al. 2013). Oil discoveries in Mesozoic structures off the coast of Israel were also recorded in drilling campaigns during the 1990s (Gardosh 2013). Additionally, new seismic data acquired in the last decade revealed the large thickness of the sedimentary column and the presence of direct hydrocarbon indicators (DHI), thus suggesting the presence of working thermogenic petroleum systems rendering the under-explored Levant Basin one of the most promising hydrocarbon provinces in the region.
Onshore, the Palmyra Basin in Syria produces oil and gas from Early Cretaceous and Middle Triassic reservoirs, respectively (Nader 2014). Gas production is also ongoing from Carboniferous sandstone (Markada Formation) in several fields onshore Syria (Lučić et al. 2003). In Lebanon, seven exploration wells have been drilled between 1947 and 1966 penetrating only down to the Upper Jurassic which is the oldest surface-exposed rock formation. Drilling failed to encounter commercial oil and gas volumes in Lebanon, probably due to (i) meteoric water washing affecting the Jurassic and post-Jurassic rock succession and (ii) off structure position of drilled wells (Nader 2014). The pre-Jurassic succession might, however, include a working petroleum system similar to the Triassic petroleum system in Syria and sealed by the Kurrachine evaporites presumed to be present in Lebanon (Beydoun and Habib 1995; Brew et al. 2001; Nader 2014). These sediments are thought to be the extension of the Upper Triassic evaporites known in the Palmyra Basin (Renouard 1955; Beydoun and Habib 1995; Brew et al. 2001; Nader 2014).
The East Mediterranean offshore, onshore, and intermediate margin seem to include several promising petroleum systems. The thermal history of the region, as well as the distribution, quality, and maturity of major source rocks, is yet unknown. Thus, we constructed a 3D thermal history model (TemisFlow™, v. 2013.2) covering an area of 315 × 315 km (grid resolution 5 × 5 km) including the Levant Basin, margin, and onshore. New source rocks’ kinetic data were produced and used in the model in order to assess the maturity and the timing of hydrocarbon generation of major source rocks and to discuss the implications on potential thermogenic petroleum systems in the study area.
Geological setting
An extensional rift phase along the northern margin of Gondwana started in the late Paleozoic and resulted in the formation of the Levant and the Palmyra basins (Fig. 1) (Garfunkel 1989; Hawie et al. 2013a; Montadert et al. 2014; Nader 2014).
Fig. 1 Regional map of the east Mediterranean showing major structural elements. Green square marks the modelled area. PS1–PS8 are pseudo wells created for calibration, yellow pseudo wells have vitrinite reflectance data, and green pseudo wells have temperature data. Orange circle marks the position of 1D extract. (Modified after Hawie et al. 2013a; Bou Daher et al. 2014; Ghalayini et al. 2014)
Successive rift pulses affected the Levant Basin until the Late Jurassic (Gardosh et al. 2010; Hawie et al. 2013a). A calm post-rift cooling and subsidence phase prevailed until the Late Cretaceous (Hawie et al. 2013a). In the Palmyra Basin, subsidence started in the Late Permian and continued till the Late Cretaceous (Ponikarov 1966; Chaimov et al. 1992). During the Late Cretaceous, the closure of the Neotethys Ocean and the collision of the Afro-Arabian and Eurasian plates started. The compressional regime persisted until the Miocene leading to the emplacement of the Syrian Arc fold belt and the inversion of Mesozoic extensional structures in the Palmyra Basin (Ponikarov 1966; Chaimov et al. 1992; Robertson 1998; Walley 1998). The two major phases of Syrian Arc folding occurred in the Coniacian (Late Cretaceous) and Late Eocene (Garfunkel 1998; Walley 1998). The initiation of the Red Sea rifting during the Oligocene/Miocene resulted in the propagation of a series of strike-slip faults northward forming the Levant Fracture System which extends from the Gulf of Aqaba to the Taurus Mountains (Beydoun 1999). The Levant Fracture System is a sinistral fault system that includes the N–S striking Dead Sea segment, the NNE–SSW central segment (Yammouneh Fault and fault splays) forming a restraining bend in Lebanon, and the N–S Ghab Fault segment (Ghalayini et al. 2014).
Lithostratigraphic framework
The onshore Jurassic–Quaternary stratigraphy was constrained based on field investigations and biostratigraphic studies (Müller et al. 2010; Hawie et al. 2013b; Nader 2014; Bou Daher et al. 2015). The offshore Jurassic–Quaternary stratigraphy was postulated mostly based on seismic interpretation (Hawie et al. 2013a). The pre-Jurassic stratigraphy was inferred from regional correlations based on published data from neighbouring countries (Brew et al. 2001; Nader 2003; Gardosh et al. 2008; Naylor et al. 2013).
The Mesozoic lithostratigraphic succession of the Levant Basin and that of onshore Lebanon realm are relatively similar and mostly dominated by carbonates (Fig. 2) (Nader 2014). In the late Cretaceous, the Afro-Arabian and Eurasian plate convergence and the emplacement of a flexural basin resulted in differential subsidence and deposition of hemipelagic/pelagic and clastic Neogene basinal fill while the marginal realms remained predominated by carbonate platforms (Fig. 2) (Hawie et al. 2013a&b). Sedimentation in the basin was almost uninterrupted while in the margin and onshore several erosion events are recorded (Müller et al. 2010; Hawie et al. 2013b). The latest ongoing erosion event is related to the uplift of Mount Lebanon and Anti-Lebanon, reaching its acme during the middle/late Miocene as a result of a transpressive regime at the Lebanese segment of the Levant Fracture System (Beydoun 1999; Gomez et al. 2006, Hawie et al. 2013a). This event led to the exposure of the Jurassic cores of the Lebanese mountains while deposition continued in the adjacent topographic lows, e.g. Bekaa Valley and the coastal areas (Fig. 1) (Khair et al. 1997; Hawie et al. 2013a; Nader 2014). The erosional thicknesses were estimated based on regional correlations and on maturity data when available (Fig. 2) (Brew et al. 2001; Nader 2003; Gardosh et al. 2008; Naylor et al. 2013).
Fig. 2 Stratigraphic chart showing the onshore sedimentary facies and their extrapolation into the offshore basin, the main petroleum system elements, and the major tectonic events (modified after Hawie et al. 2013a).
Several volcanic episodes are recorded along the eastern margin of the Levant Basin (Fig. 2). Late Jurassic–Early Cretaceous alkaline volcanism is found in north Lebanon and completely absent in south Lebanon (Dubertret 1955; Nader 2014). Wilson (1992) and Garfunkel (1992) attributed this regional intermittent volcanism to mantle plume activity in the Levant region. Another episode of volcanism occurred in the late Cenozoic (Fig. 2). These alkaline volcanics are linked to open cracks related to the Levant Fracture System permitting local deep decompression and magma ascent (Adiyaman and Chorowicz 2002). Abdel-Rahman and Nassar (2004) attributed the Pliocene alkali basalts of northern Lebanon to a transtensional regime at the junction of the Lebanese restraining bend and the Ghab segment of the Levant Fracture System.
Data source: 3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshore–onshore Lebanon. Samer Bou Daher, Mathieu Ducros, Pauline Michel, Nicolas Hawie, Fadi H. Nader, Ralf Littke. 2016
Petroleum Systems of Lebanon: recent advances and future potential. Ramadan Ghalayini, Fadi. H. Nader,Samier Bou Daher, Nicolas Hawie, Lama Inati. 2018
Следующий Бассейн: Elat - Dead Sea