Recent Hydrocarbon Exploration In Greece, 2004

A review of recent hydrocarbon exploration in Greece and its potential A. Mavromatidis Technological Educational Institute of Crete, Dept. of Natural Resources & Environment, Chania, Greece, [email protected]

V. C. Kelessidis Technical University of Crete, Dept. of Mineral Resources Engineering, Chania, Greece

D. G. Monopolis Technical University of Crete, Dept. of Mineral Resources Engineering, Chania, Greece Paper presented at the 1st International Conference on Advances in Mineral Resources Management and Environmental Geotechnology, 7-9 June 2004, Chania - Crete – Greece ABSTRACT The paper reviews the recent exploration activity of hydrocarbons in Greece and neighbouring Albania and Turkey. Emphasises the relevance of the prospects in these neighbouring countries and those identified in Greece, and finally accentuates the importance of a new exploration strategy in Greece. With only few deep exploration wells drilled the last years, none offshore, the area should be set for a more extensive exploration effort and a future announcement for a new onshore and/or offshore licensing round by the new Greek government should be pursued. 1. INTRODUCTION Hydrocarbon (HC) exploration in Greece has been under way from the 1860s. A comprehensive review for the activity until 1977 has been done by Monopolis (1977) and until 2000 by Xenopoulos (2000). Early exploration focused on the abundant surface seepage of oil in the area of western Greece. Then, after decades, in 1972, it focused in the Prinos area northeast of the country, in 1980s in south western Greece at the Katakolon area and further north in Epanomi area and finally in 2000s again in western Greece. Exploration results to date are not encouraging since only one viable field was discovered, in Prinos area, while the small offshore and onshore oil and gas

fields in Katakolon and the gas field in Epanomi have not yet been developed. It is worth mentioning that in Albania there are about 25 oil and gas fields while in Turkey there are more than 16 oil and gas fields in Thrace basin and few in central west Turkey. Based only on published data a connection between the proven fields in neighbouring countries around Greece and the potential of the explored areas in Greece is attempted in this paper. The approach can help establish the relationship between tectonostratigraphic basin evolution and potential resources and can assist in prospectivity assessment. 2. IONIAN ZONE, ALBANIA AND WESTERN GREECE 2.1 Albania The Ionian zone is the main HC producing region in Albania with recoverable reserves in Tertiary clastic and carbonate reservoirs (Fig. 1). These include giant heavy oil fields with low recovery factors such as the Patos-marinza field which has approximately 2 billion barrels in place (Albpetrol, 1993). The zone has a welldeveloped Tethyan stratigraphy reaching a total estimated thickness of 10 km or more (Velaj et al., 1999). OMV is the biggest international player in onshore Albania. OMV has also licenses in the Patos-Marinza field and offshore 1

Figure 1. Licensing status and exploration activity in Albania, Greece and western Turkey. Major tectonic zones, exploration blocks, oil and gas fields, major oil seeps and recent drilled wells in Greece are also shown (Ait = Aitoloakarnania, Ap-1 = Apollo-1, Ar-1 = Artemis-1, De-1 = Demetra-1, Ev-1 = Evinos-1, Ion = Ioannina, NWP = Northwest Peloponnesos, TS-1 = Trifos South-1).

Albania block (http://www.omv.com). Geophysical surveys have attested the highly prospective carbonate reservoirs. This deep carbonate section, overlain by evaporates, holds the potential for future discoveries in Albania (Nieuwland et al., 2001).

2.2 Western Greece The Greek Ionian zone area, should be active oil or gas province since there are oil seeps distributed in various locations and is a continuation of the proven Albanian fields (Fig. 1). However, the only proven discovery is the oil-gas field offshore in Katakolon area. The field discovered in 1981, and the producing horizon is the Eocene-Cretaceous carbonates of a paleostructure, unconformably covered by 2

clastic Neogene sediments (Roussos & Marnelis, 1995) with an estimated 40 million bbl oil in place and 10 to 12 million bbl recoverable oil (Maniatakis & Stabolis, 2003). The Ionian zone is composed of Tertiary clastics that underlain by thick Mesozoic carbonates which in turn are underlain by Late Triassic evaporites. All exploration wells have stopped in or never reached the Late Triassic evaporitic section which has never been penetrated. Triassic evaporites consist of halite, gypsum, and anhydrite with interbedded dolomite and thin organic rich shales. The original thickness is uncertain but estimates raise it to more than 2000m (IGRS, 1966; Mavromatidis, 2004). On top of this lie the carbonate successions of Pantokrator limestones which are more than 1500m thick (IGRS, 1966). Hence, the aim for future exploration and the potential for oil or gas discovery should be at locations with total section thickness of more than 3500m or more than 2000m in case drilling starts from surface evaporites. Exposed or shallowly buried carbonate anticlines are present throughout the Ionian zone. These carbonates, limestones with tight matrix porosity, which are abundant across the area, are not expected to form effective seals as they are unlikely to have escaped bacterial degradation and fracturing during Tertiary compression (Mavromatidis, 2004). However, the traps below the evaporites, the deep plays are particularly attractive. These are the deeply buried clastic and carbonates that may have fortified from bacterial degradation so that good quality of hydrocarbons may have been preserved (Mavromatidis, 2004). Such traps are evident in southern Albania (Velaj et al., 1999; Nieuwland et al., 2001). In late 1995, the Greek state oil company Hellenic Petroleum (HP) announced for the first time after 1980 an international tender for six regions of western Greece (Fig. 1) (three on land and three offshore), for a total area of 12139 km2. The Katakolo field has been included in the tendering process but there was interest only on exploitation without the preceding exploration stage, required by the tender and thus the Greek state did not proceeded further (Maniatakis & Stabolis,

2003). In 1997, the government signed four contracts for oil exploration and exploitation in four stretches near Ioannina and the northwest Peloponnesos (NWP), two of them between Enterprise Oil and the Greek State (HP) and the other two contracts in Aitoloakarnania and Gulf of Patraikos, between Triton Ltd. and the Greek State (HP). Enterprise Oil, in its two concessions has carried out geophysical research which covered 700 km of seismic lines. The processing and interpretation of the seismic readings in the NWP has led to the determination of the position of two drilling sites at a depth of 2500m each, while for Ioannina has led to the determination of the position of one well for a target depth of about 4000m. Triton Ltd. has also carried out a broad programme of seismic tracings on the land area of Aitoloakarnania which has led to the determination of the position of two drilling sites, one at Evinos at a depth of approximately 1500m and a second one in the Trifos area, at about the same depth. In the sea area of the Gulf of Patraikos, Triton Ltd. has carried out seismic tracings of 1000km, with 4000m of cables (long offsets method). The processing and interpretation of these tracings aimed at a targeted depth of 3000m below sea level. By late 2001, all exploration and drilling activities finalised in a grotesque manner. Enterprise Oil drilled two wells in NWP, Artemis-1 and Apollo-1 in the year 2000, and one well, Demetra-1, in the Ioannina area, drilled in 2001. Artemis-1 is located on a faulted fold with a top seal of Oligocene flysch. The target was the Ionian basinal carbonates underneath the flysch. The reservoir interval was prognosed to consist of fractured carbonates of Late Cretaceous to Eocene age which are productive further up north in Albania and in the central Adriatic fields offshore Italy. Drilling proceeded to a total depth of 2375m. The well encountered some oil shows and the well was plugged and abandoned (P&A). The Apollo-1 well was located in the Gavrovo Zone, within the Hellenide fold and thrust belt. The structure targeted by the Apollo1 was a faulted fold, having the flysch as a seal rock. Only two key lithological intervals were 3

present in the well, namely the Flysch and the Gavrovo carbonates, the latter that comprise the reservoir. The Gavrovo carbonates have rarely been drilled in Greece. The reservoir interval was prognosed to consist of fractured and karstified platform carbonates, analogues of which are productive in the greater Adriatic and southern Italy region. The well proceeded to a total depth of 1710m and was P&A. The Demetra-1 well was drilled in 2001. Original target depth for Demetra-1 well was at 4000m aiming at penetrating the thick evaporitic section never penetrated before but this also did not materialize in this attempt. A dome structure was delineated from seismic profiles at that depth and the well was spudded and drilled over a period of five months and preceded with no significant problems. However, it did not succeed in penetrating the evaporites with reports indicating that drillers had encountered unexpectedly high pressures, while still in the evaporitic section, which proved impossible to overcome, even after the unsuccessful attempt to sidetrack the well. These problems increased the drilling expenditure significantly and combined with the acquisition of the operator (Enterprise Oil) by Shell, a shift of priorities of the new owner led to the decision for the well to be P&A. In 2000, Triton Ltd. drilled two wells in Aitoloakarnania, named Trifos South-1 and Evinos-1. Triton Ltd. did not execute the agreed drilling program in the Gulf of Patraikos due to company’s management decision after the takeover by Amerada Hess. Trifos South-1 was planned to drill to a target of Ionian Zone basinal carbonates, sealed by Oligocene flysch. This reservoir/seal interval was prognosed to be in a subthrust setting, overthrust by Triassic evaporites. However, during drilling these evaporites were found to be thicker and the well stopped within these evaporites at 1509 m. Commitment depth for the well was 1500 m. This well failed to drill to the objective reservoir and failed to test the play. It was P&A (with minor oil and gas shows). Evinos-1 was planned to drill Gavrovo Zone platform carbonates, sealed by Oligocene flysch. The well was drilled to commitment

depth of 1500m and stopped at 1508m. Minor gas shows and poor oil shows were encountered in the basal flysch and within the carbonates and the well was P&A. The most likely cause for dry hole is absence of trap at the well location. Even though the recent activity in western Greece has proven unsuccessful, the wealth of subsurface data that has been acquired with state of the art technology, never done before at these large depths, as in Demetra-1, should be made available for further investigation and analysis so that a better picture of western Greece subsurface geological setting to be drawn and the causes of the unexpected high pressures to be determined. This will aid in the delineation of future attempts for oil exploration which should not be ceased. 3. GRABENS IN WESTERN TURKEY AND MESOHELLENIC TRENCH IN CENTRAL GREECE 3.1 Grabens in western Turkey In an extensional regime in western Anatolia (Turkey), E-W grabens formed during the Pliocene and locally intersected older Miocene formed grabens that contained lacustrine bituminous shales and fan delta sediments (Yilmaz & Gelisli, 2002) (Fig. 1). The Alaşehir Graben is an example of such configuration. It contains possible traps as well as high potential for HC generation. Geochemical analyses show that Early-Mid Miocene lacustrine shales are capable of producing oil (Yilmaz & Gelisli, 2002). 3.2 Mesohellenic trench in central Greece The Mesohellenic basin trends SSE-NNW is 130km long and 40km wide and is located in the sub pelagonian zone (Fig. 1). Two depocentres, more than 4200m and 3200m thick, have been recognized of Middle Eocene to Middle Miocene age, where submarine fans of sandstones and shales have accumulated unconformably over a sub pelagonian complex. Source rocks and possible stratigraphically trapped reservoirs have been identified with geochemical analyses (Kontopoulos et al., 1999; 4

Avramidis et al., 2002). All indications from the area however show that the organic matter is immature and thus the generation of gas is of biogenic origin. 4. THRACE BASIN, NORTHWESTERN TURKEY AND TERTIARY BASINS, NORTH AND EASTERN GREECE 4.1 Thrace Basin, northwestern Turkey The Thrace basin located in European Turkey covers an area of some 20000 km2. It has developed as a fore-arc basin between the medial Eocene to Oligocene. The basin is filled with turbidites in its interior and clastics and carbonates on the margins (Görür & Okay, 1996). Further south in the Saros Gulf there is a producing oil and gas field (Coskun, 2000). Exploration has mainly targeted deep plays in Eocene age sediments which resulted in several discoveries. Currently there are 14 commercial gas fields and 3 oil fields. A recent discovery is the Gocerler gas field, a discovery made from shallower Oligocene sediments (http://www.amityoil.com.au). Major explorer is Amity Oil which holds seven exploration licences in the area together with Turkiye Petrolleri Anonim Ortakligi and Omax Resources. 4.2 Tertiary basins, north and eastern Greece In eastern Greece exploration was oriented towards the post-orogenic Paleogene and younger Neogene basins. The main tectonic regime that controlled their evolution was extensional. The stratigraphy includes Eocene reefal limestones, thick Eocene to Oligocene marine clastic sediments, and Neogene terrigenous deposits with extended Messinian evaporites. Potential source rocks for gas and oil generation have been discovered in Eocene and Miocene sediments. Traps include rollover anticlines, faulted structures, and stratigraphic features in Eocene reefal limestones, Eocene Oligocene sandstones, and Neogene sands. Trapping ability also exists in fractured Mesozoic formations (Fig.1), although they are

not source rocks but oil comes from lateral migration from younger formations. The Epanomi gas field was discovered in 1988 by HP, with recoverable reserves of 0.5 billion Nm3 of natural gas (Maniatakis & Stabolis, 2003). The structure is formed by the paleoerosional surface of Mesozoic metamorphic limestones buried below Tertiary clastic sediments (Roussos & Marnelis, 1995). The field has not been explored to date. Miocene sands, capped by thick salt and evaporite sections, form the reservoir for Prinos field. Source rocks were considered to be marine shales of Upper Miocene age. The Prinos structure is a graben bounded by sealing faults which dip towards the center of the basin. The Prinos oil and South Kavala gas fields were discovered by the Oceanic company in 1973 and exploited by North Aegean Petroleum Company (NAPC). Production terminated in 1993 for the South Kavala field and 1998 for the Prinos field. However, a new oil field, namely North Prinos, was discovered in 1994 by NAPC, with HP participating with a 35% interest Maximum production was estimated at 3,000 barrels per day. In 1999, NAPC withdrew from the region and operation has since been undertaken by the newly formed Kavala Oil. There is recent exploration activity in the Prinos area, undertaken by the operator, Kavala Oil. Information has been collected from news agencies and company announcements since no scientific information is publicly available. A well was drilled in the E1A prospect in June 2000 and two producing zones were discovered at a depth of around 2900m. Although tests have shown that it contained much less H2S that the oil produced from Prinos and with estimates of recoverable reserves of about 13 million bbl (Kavalanet, 2002), it was a very tight reservoir requiring hydraulic fracturing. In addition, the building of an exploitation platform should have been necessary, with an investment of around 50 million US$, since it was further away from the existing platforms. Exploitation was thus deemed non attractive because of economic situations at that time and has thus been 5

postponed for later years. In October 2003 there was the buyout of the major shareholder of Kavala Oil (Eurotechniki) by Regal Petroleum which now holds about 60% of Kavala Oil. Following the buyout, a well was drilled in November 2003 with a cost of 8,5 million US$ in the Kallirachi prospect, which logged a 200m gross pay zone with 61m of sweet oil net pay at a total depth of 2556m. Although no results of any well testing have been officially reported, independent consultant’s pre-drill estimates show a maximum of around 227 million bbl of recoverable oil, (Kavalanet, 2003; Oil&Gas J. Online, 2004). The announced discovery is expected to spur drilling activity with probably four to five wells and an investment of around 150 million US$ already announced, raising more the expectations for further drilling activity (Kavalanet, 2003). However, there are no plans for extending the exploration activity to the potentially hydrocarbon bearing reservoirs in the areas east of the island of Thassos. 5. DISCUSSION It is obvious that the exploration success in Greece for finding HC till present time is not very encouraging regarding further exploration. The majority of the wells, drilled before 90s, were selected mainly on the basis of surface geology with poor geophysical support. Geological surveys although locally controlled by some rather deep wells (> 3500m) have not yet been capable of providing a comprehensive and reliable picture of the relatively deep geological structure. However, in western Greece there are basins with significant HC potential and merits for exploration. All requirements for hydrocarbon accumulations are satisfied in the Ionian basin, namely source rocks (Rigakis & Karakitsios, 1998), oil generation (Mavromatidis, 2000), reservoir, seal rocks and palaeorelief trap structures (Zelilidis et al., 2003). In this area there is significant amount of geological data. This part of the country has already attracted oil exploration interest since early in this century

and has been covered by detailed surface geological surveys including mapping of 1:50000. Western Greece is covered by northwest-southeast trending geotectonic units constituting the southern prolongation of the oil producing Albania (Fig. 1). It can be safely stated that there is a great possibility for commercial production to be established in western Greece which is an area of active oil seeps, asphalt saturated strata, repeated shows in wells and thick dark coloured bituminous carbonate rocks. In Katakolon, exploration has proven the existence of the oil field, in water depths of more than 200m, which awaits now exploitation. This should proceed with the appraisal and development wells. While this task at the time of its discovery was deemed very risky and difficult and therefore not undertaken, now with the recent technological developments and why not, the breakthroughs in drilling technology, for deep well drilling (Jenkins & Roger, 1995; Judzis & Baowes, 1997), for extended reach wells (Cruse et al., 1997; Avignon & Simondin, 2002), and with the less expensive Coil Tubing Drilling (CTD), the water depths of 200m are tractable leading to the suggestions for revisiting the prospects in Katakolon (see Kelessidis & Mpandelis, 2003, for listing of CTD activities around the world and Konstantakopoulos et al., 2000, for an overview of CTD). Similar statements were expressed before (Xenopoulos, 2000), who claims further that based on data analysis from seismic and well profiles (available until the year 2000), there were good chances for discovering more oil not only in western Greece but in other areas of Greece as well. The Messohelenic basin is considered to be a very high risk area for HC exploration in which no commercial discoveries have yet been made. One may be tempted to think of similarities with the Alaşehir graben where there is evidence for HC generation. But this is not true since Alaşehir Graben is not in the subpelagonian zone and the two areas have not the same geological background. Hence, the Messohelenic basin should be a region with very low exploration priority. The Epanomi gas field has similarities with 6

the gas fields in Thrace Basin, one is the lithology and the second is the tectonic province. The Thrace Basin, which is under intensive exploration activity at the moment, is an extension of the Axios-Perirodopic zone in Greece where the Epanomi oil-gas field belongs to. The Prinos field has also similar lithology with Thrace Basin units and some claim that gas fields in Marmara Sea in Turkey produced from the same carbonates as in Prinos oilfield (Coskun, 2000). 6. CONCLUSIONS Is there plenty of oil or gas in Greece and will it ever be found? It is the ever-occurring question to every Greek since the beginning of the 19th century when oil was crowned as the king of energy source. University of Athens professor Georgalas starts his 1937 inaugural lecture with this same question and goes on saying ‘of course there are hopes for existence of oil and gas fields in Greece stemming from scientific data but to answer this question fully we must do a lot of drilling’ (Monopolis, 1977). Today, this question has yet to be answered and if posed we would answer it exactly the same way, even though ever since 1937 there have been more than 200 wells that have been drilled (with about 60 of them in Prinos field, of which about 40 are production and injection wells). This drilling activity resulted in the discoveries of Prinos, Katakolon and Epanomi fields. This low level activity leads us to claim Greece as the least explored country not only in the Mediterranean region but also in central, northern and eastern Europe as well. Many factors have contributed to this low exploration activity in Greece, from the small sedimentary basins, both onshore and offshore, to the large water depths offshore. Current drilling technology enables the successful penetration in the deep horizons where oil or gas is premised to be, as analyzed above, as well as to large water depths for offshore exploration. All countries neighboring Greece exceed Greece in daily oil production. The geologic setting in all these countries is both similar and indicative of containing commercial

oil accumulations. The licensing round held in 1996, the first one after 1980, awarded six concessions and none of these prospects materialized. In May 2002, Greece announced that it would hold its second oil exploration licensing by early 2004. The round would aim to include both offshore and onshore areas in north-western and southwestern Greece, plus unexplored blocks in the Ionian Sea (http://www.aapg.org, http: //www.eia.doe.gov). However, as of March 2004, no such undertaking has occurred when at the same time all countries in south Mediterranean area (e.g. Albania, Bulgaria, Croatia, Egypt, Israel, Italy, Libya, Malta, Serbia-Montenegro, Romania, Syria, Turkey) have provided licences to oil companies and exploration projects are on progress. An aggressive oil exploration campaign should thus be undertaken in the immediate future. Exploration should be undertaken with strong commitment from the Greek State, while exploitation should be left for third parties (Monopolis, 1989). What is necessary is the commitment of the new Greek government that it will pursue the exploration and exploitation activity with new licensing rounds, and remembering the golden rule for discovering oil and gas fields, that is, unless we drill we will never find out what is in the subsurface. REFERENCES Albetrol (1993). Petroleum exploration opportunities in Albania: 1st onshore licensing round in Albania. Western Geophysical, p12. Avignon, B. and Simondin, A. (2002). Deep Water Drilling Performance, Paper SPE 77356 presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 29 September-2 October. Avramidis, P., Zelilidis, A., Vakalas, I. and Kontopoulos, N. (2002). Interactions between tectonic activity and eustatic sea-level changes in the Pindos foreland and Mesohellenic piggy-back basins, NW Greece : Basin evolution and hydrocarbon potential. Journal of Petroleum Geology (25): 53-82. Coskun, B. (2000). North Anatolian Fault-Saros Gulf relationships and their relevance to hydrocarbon exploration, northern Aegean Sea, Turkey. Marine and Petroleum Geology (17): 751-772. Görür, N. and Okay, A.I. (1996). A fore-arc origin for the Thrace basin, NW Turkey. Geol. Rundsch (85): 662668.

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Cruse, P. C., Tada, H., Takeouchi, T. (1997) Horizontal well and extended reach technologies with reported problem areas and operational practice in North America and Europe, Paper SPE 38270 presented at the SPE Western Regional Meeting, Long Beach, CA, 25-27 June. http://www.aapg.org/explorer/2003/08aug/licensing.cfm http://www.amityoil.com.au http://www.eia.doe.gov/emeu/cabs/greece.html http://www.omv.com IGRS-IFP. (1966). Etude geologique de l’ Epire (Grece nord-occidentale): Editions Technip, Paris, France. Jenkins P.E., Roger W. (1995). New Concepts Lower Deep Water Drilling Costs, Paper SPE 30466 presented at the Annual Technical Conference & Exhibition, Dallas, TX, U.S.A., 22-25 October. Judgis, A. and Bowes, C. (1997), Extended reach drilling: managing, networking, guidelines and lessons learned, Paper SPE 37573 presented atSPE/IADC Drilling Conference, Amsterdam, Netherlands, March 4 – 6. Kavalanet 2002, www.kavalanet.gr Kavalanet 2003, www.kavalanet.gr Kelessidis, V. C. and Mpandelis, G. E., (2003). Flow Patterns and Minimum Suspension Velocity for Efficient Cuttings Transport in Horizontal and Deviated Wells in Coiled-Tubing Drilling, Paper SPE 81746 presented at the SPE/ICoTA Coiled Tubing Conference, Houston, TX, 8–9 April (2003). Kontopoulos, N., Fokianou, T., Zelilidis, A., Alexiadis, C. and Rigakis, N. (1999). Hydrocarbon potential of the middle eocene-middle Miocene Mesohellenic piggyback basin (central greece): A case study. Marine and Petroleum Geology (16): 811-824. Konstantakopoulos, I., Dimitrellou, I. and Stamataki, S., (2000). Innovative technologies expanding current drilling capabilities. Proceedings, 3rd Conference on Mineral Resources, Athens, Greece, Nov. 23-23. Maniatakis, D. L. and Stabolis, K. (2003). Chapter 3: Petroleum products, Exploration and Production of Hydrocarbons in Greece, in Market Energy in Greece, ICAP & DELOS Report, www.energia.gr Mavromatidis, A. (2000). Maturity modelling of western Greece and Albania. Enterprise Oil Ltd.., Unpublished report: pp.150. Mavromatidis, A. (2004). Review of the sub-evaporitic lithology in the Ionian Basin, western Greece and hydrocarbon prospectivity, Proceedings, 5th International Symposium on Eastern Mediterranean Geology, Thessaloniki, Greece, April 14-20. Monopolis, D. G. (1977). Oil exploration in Greece, Proceedings, Conference ‘The Energy Problem of Greek Economy Today’, organized by Technical Chamber of Greece, Athens, May 23 – 28. Monopolis, D. G. (1989). Oil Exploration in Greece. Mineral Wealth, 60, 187-193. Nieuwland, D.A., Oudmayer, B.C. and Valbona, U. (2001). The tectonic development of Albania: explanation and prediction of structural styles. Marine and Petroleum Geology (18): 161-177.

Oil&GasJournal Online (2004) Exploration/Development. Editorial announcement. Rigakis, N. and Karakitsios, V. (1998). The source rock horizons of the Ionian Basin (NW Greece). Marine and Petroleum Geology (15): 593-617. Roussos, N. and Marnelis, F. (1995). Greece Licensing Round to Focus on Western Sedimentary Basins. Oil & Gas Journal (March 6). Velaj, T., Davison I., Serjani A. and Aslop I. (1999). Thrust tectonics and the role of evaporites in the Ionian Zone of the Albanides. The American Association of Petroleum Geologists Bulletin (83) (9): 1408-1425. Xenopoulos, S., 2000, Exploration and exploitation of hydrocarbons in Greece: Current activities – perspectives, Proceedings, 3rd Conference on Mineral Resources, Athens, Greece, Nov. 22-23. Yilmaz, M. and Gelisli, K. (2002). Stratigraphic-structural interpretation and hydrocarbon potential of the Alaşehir Graben, western Turkey. Petroleum Geoscience (9): 277-282. Zelilidis, A., Piper, D. J., Vakalas, I., Avramidis, P. and Getsos, K. (2003). Oil and Gas Plays in Albania: Do Equivalent Plays Exist in Greece? Journal of Petroleum Geology (26): 29-48.

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