Journal of Petroleum Geology, Vol. 41(2), April 2018, pp 189-214 189 PETROLEUM SYSTEMS OF LEBANON: AN UPDATE AND REVIEW R. Ghalayini1*, F. H. Nader2, S. Bou Daher3**, N. Hawie4 and W. E. Chbat5 This paper presents a new interpretation of the Levant margin, offshore Lebanon, with a review of Lebanese onshore geology and a new evaluation of the petroleum systems of the Eastern Mediterranean. Here, we divide the Lebanese onshore and offshore into four domains: the distal Levant Basin, the Lattakia Ridge, the Levant margin, and the onshore. Each domain is characterised by a particular structural style and stratigraphic architecture, resulting in different source-reservoir-trap configurations. This new division draws attention to specific areas of exploration interest in which there are distinct petroleum systems. Following a review of previously published data, this study presents new results from stratigraphic, structural and geochemical investigations. The results include a new interpretation of the Levant margin, focussing on the carbonate-dominated stratigraphy of this area and its petroleum potential. New petroleum systems charts are presented for each of the four domains to refine and summarize the updated geological knowledge. INTRODUCTION of proven natural gas reserves in nearby parts of the Levant Basin between 2006 and 2015; fields include Lebanon, part of the greater Levant region, is located Tamar, Leviathan, Aphrodite and Zohr (Fig. 2). on the active NW margin of the Arabian plate, the Onshore, in Syria, recoverable reserves are estimated margin being largely defined by the left-lateral Levant at about 2.5 billion (B) brl of oil and about 8.5 TCF of Fracture System (LFS) (Fig. 1) (Nader, 2014 a,b). gas, with fields located in the Palmyrides, the Euphrates To the east is the petroliferous Palmyride fold-and- graben, and the Sinjar high (Barrier et al., 2014). thrust belt and to the west the stable foreland of the Recent exploration successes in the Levant region Levant Basin. Lebanon and the adjacent offshore are have prompted the Lebanese government to acquire an considered to have significant exploration potential. extensive volume of multi-client 3D seismic data to This is based on the discovery of more than 70 TCF aid offshore exploration. An improved understanding 1 Independent consultant. 4 BeicipFranlab, 232 Av. de Bois-Préau, 92502 Rueil- 2 IFP Energies nouvelles, 1 & 4 Av. de Bois-Préau, 92852 Malmaison, France. Rueil-Malmaison, France. 5 Lebanese Petroleum Administration, Georges Akouri 3 Energy and Mineral Resources Group (EMR), Institute Street, Beirut, Lebanon. of Geology and Geochemistry of Petroleum and Coal, ** now at: Department of Geosciences and Natural RWTH Aachen University, Lochnerstrasse 4-20, 52056 Resource Management, University of Copenhagen, Øster Aachen, Germany. Volgade 10, 1350 Copenhagen, Denmark. * corresponding author: Key words: Levant Basin, Palmyra Basin, Lebanon, [email protected] petroleum system, Eastern Mediterranean. © 2018 The Authors. Journal of Petroleum Geology © 2018 Scientific Press Ltd Ghalayini.indd 189 02/03/2018 15:05:27 190 Petroleum systems of Lebanon: an update and review 34°E 35°E 36°E 37°E 38°E 35°N Bilas Block 35°N N Levant Lattakia ridge Restraining bend Figure 14 Figure 13 Jhar Fault 3 2 Figure 1 Mid Bekaa Fault 1 1 Anti-Lebanon Northernammouneh Mount Lebanon Fault 34°N Y N T 34°N Figure 12 SI E L Bekaa Valley B A BA D n Damour Fault Y R i L M Saida Fault Serghaya Fault A E S F O L P R I D Southern B a s Roum Fault Y L M 30° E 34° E t Saida Tyr Mount Lebanon P A n & ANATOLIAN PLATE Plateau N LATTAKIA BASIN TE 36° N m e v a e t s L Golan y S Heights e MEDITERRANEAN r u t c SEA a 33°N r 33°N F t Carmel Fault EratosthenesSeamount n a v Nile Delta e 32° N L LEVANT BASIN ARABIAN PLA 0 100 AFRICAN PLATE Km Key to Legend Anticline Strike-slip faults Normal fault Cenozoic 1 Qartaba ant. 1 Terbol ant. Syncline Inverted normal fault Currently active structures Cretaceous 2 Sir Ed Deniye ant. Mid-Bekaa fault Reverse fault Neogene Jurassic 0 25 50 100 Km Potential fault extension Major structures Paleogene Volcanics Fig. 1. Main structural elements of Lebanon, the Levant Basin and part of Syria. Map compiled from Barrier et al., 2014; Ghalayini et al., 2014; Ghalayini et al., 2016; and Brew et al., 2001. of the geology of the Levant region has been acquired into geological domains based on stratigraphic, from interpretations of this data-set by academic and structural and geochemical data (Fig. 2). Aspects of the industrial research partners. The results of these studies petroleum geology of each domain (potential source include: (i) a new stratigraphic model for the Levant rocks, reservoirs and traps) are discussed, and new Basin based on seismic data, extensive fieldwork, exploration objectives are tentatively identified. These and forward modelling (Hawie et al., 2013, 2014, results serve as a basis for an improved understanding 2015); (ii) a more detailed structural framework of the petroleum potential of on- and offshore Lebanon. for the Levant Basin and margin based on new 3D seismic data interpretation and analogue modelling Exploration history (Ghalayini et al., 2014, 2016, 2017); (iii) a thorough Petroleum exploration in Lebanon began in the 1930s geochemical assessment of source rock potential (Wetzel 1974; Nader, 2014a). Twelve companies supported by extensive sampling onshore and regional were actively involved in exploration in the country, basin modelling, providing an updated evaluation of among which the Compagnie Libanaise des Pétroles the hydrocarbon potential of Lebanon (Bou Daher et (CLP) and the Syria Petroleum Company (SPC) were al., 2014, 2016); and (iv) an improved model of the the largest (Wetzel, 1974). The SPC, a subsidiary of crustal structure of the Levant Basin confirmed by the Iraq Petroleum Company, drilled the first well deep seismic and gravity modelling (Inati et al., 2016). (at Terbol: location in Fig. 2) in 1947 but failed to The purpose of this paper is to summarize the find economic accumulations of hydrocarbons. The results of recent geological and petroleum-related company has since relinquished its concessions in investigations in Lebanon, and to interpret new Lebanon. The CLP drilled five wells in the Bekaa seismic lines located off the northern and southern valley between 1953 and 1964, four with foreign parts of the country. A new interpretation of the partners, but without any commercial success, and Levant margin (offshore Lebanon) is presented with held concessions covering about 5200 km2. In 1970, a focus on carbonate-related prospects, reflecting the first offshore seismic data was acquired by Oxoco the fact that associated plays have attracted major off north Lebanon, and in 1971 Delta acquired 320 km attention following the recent Zohr discovery in of 2D seismic lines in addition to a gravity survey on offshore Egypt (Fig. 2). The Levant region is divided the Shaheen permit. Ghalayini.indd 190 02/03/2018 15:05:28 R. Ghalayini et al. 191 33°E 34°E 35°E 36°E 37°E 35°N 35°N Lattakia Ridge structural traps Al Rasem N biogenic + thermogenic system Terbol Ash Bilas Ebrine ElQaa Shaer Al Mahr North Al Faid Jihar Deep Basin Palmyra 34°N structural traps Cherife 34°N biogenic system structural traps Kumkum Onshore domain Abu Rabah thermogenic system Qasa Levant margin Tell Znoub stratigraphic traps Sohmor Lattakia Ridge domain Aphrodite biogenic + thermogenic Yohmor Tanin system Adloun Levant margin domain Karish Deep basin domain Onshore domain 33°N Leviathan Gas field 33°N Zohr Tamar 0 100 200 Km Dolphin Dalit 33°E 34°E 35°E 36°E 37°E Fig. 2. Map showing the geological domains of Lebanon as discussed in this study, together with hydrocarbon discoveries in nearby countries. The acquisition of regional 2D seismic refl ection Cretaceous until the present day. Accelerated roll-back surveys by Spectrum and TGS in 2000 and 2002, of the subduction zone along the Hellenic-Cyprus arc respectively, led to the mapping of several promising occurred during the Tortonian (Le Pichon and Kreamer, leads in sub-Messinian units. Between 2006 and 2010), which resulted in renewed fold-thrust activity 2012, PGS then acquired 9700 km2 of 3D seismic in the mid–Late Miocene along the Lattakia Ridge data; Spectrum acquired an additional 5172 km2 of (Hall et al., 2005; Robertson et al., 1996). Westward 3D data between 2012 and 2013 in the deep-water tectonic escape of the Anatolian microplate took place offshore. These new data have indicated that Lebanon in the Messinian – Pliocene, with a component of has promising hydrocarbon potential (Roberts and anticlockwise rotation (Le Pichon and Kreamer, 2010; Peace, 2007), and the Lebanese Government recently Sengor and Yilmaz, 1981) resulting in reactivation of (2017) issued a series of decrees to regulate future the Lattakia Ridge with sinistral strike-slip motion offshore exploration activities. A joint venture of three (Hall et al., 2005). These regional-scale geodynamic companies, Total, ENI and Novatek, was awarded events were marked in both the Levant Basin and in exploration licenses by the Lebanese Government in onshore Lebanon by post-Oligocene reactivation of January 2018 for two blocks offshore south and central structures, and by a decrease in strike-slip activity Lebanon, respectively. on the LFS (Freund et al., 1970; Ghalayini et al., 2014; Le Pichon and Gaulier, 1988; Quennell, 1984). Tectonic and crustal setting Accelerated uplift of pre-existing structures such as The present structural framework of on- and offshore Mount Lebanon has taken place from the Late Miocene Lebanon is dominated by the Levant Fracture System to the present day (Walley, 1998; Ghalayini et al., (LFS) and the Lattakia Ridge System (Fig.