Eight Wells, Four Drillships: How Türkiye Documents Its Offshore Activity in the Eastern Mediterranean

Why It Matters

Türkiye ties its sovereign-rights claims in the Eastern Mediterranean to a paper trail: state licences, UN filings, a bilateral delimitation agreement and physical activity by a national drilling and survey fleet. That fleet is made up of the drillships Fatih, Yavuz, Kanuni and Abdülhamid Han and the seismic vessels Oruç Reis and Barbaros Hayreddin Paşa. Turkish sources count eight major wells drilled so far. How far such activity strengthens a legal claim is contested, and the Greek Cypriot, Greek and EU objections are set out below in their own words.

Background

The offshore record is best read as a sequence of legal acts and field operations. Both are listed in the chronology and tables below, so readers can check them against primary sources such as the Primary Document Library.

Chronology of the documentary chain

• 2003–2010: The Greek Cypriot Administration of Southern Cyprus (GCASC; the internationally recognised “Republic of Cyprus”) signs EEZ agreements with Egypt (2003), Lebanon (2007) and Israel (2010). Türkiye objects to all three. It says the Egypt agreement overlaps its continental shelf, with GCASC Blocks 1, 4, 5, 6 and 7 touching areas Ankara claims. See the 2003 Egypt–Greek Cypriot EEZ analysis.
• From 2004: Türkiye files Eastern Mediterranean continental shelf coordinates with the United Nations.
• 2009 and 2012: The Turkish Petroleum Corporation (TPAO) receives exploration licences for Eastern Mediterranean areas.
• 19 September 2011: GCASC begins unilateral drilling.
• 21 September 2011: Türkiye and the Turkish Republic of Northern Cyprus (TRNC) sign a Continental Shelf Delimitation Agreement.
• 27 November 2019: Türkiye and Libya sign a Memorandum of Understanding on maritime jurisdiction areas.
• 18 March 2020: Türkiye registers the outer limits of its continental shelf with the UN.
• 16 April and 12 June 2025: Türkiye unveils its Marine Spatial Planning and records it with IOC-UNESCO. A Presidential Circular of 24 July 2025 then creates an inter-agency coordination board under the Ministry of Foreign Affairs.

For how coordinates and median lines work on such maps, see How to Read a Maritime Boundary Map.

The vessels

Vessel	Type	Role in the record
Fatih	Deep-sea drillship	Part of the national drilling fleet; also used beyond the Mediterranean, including the Black Sea
Yavuz	Deep-sea drillship	Part of the national drilling fleet
Kanuni	Deep-sea drillship	Part of the national drilling fleet
Abdülhamid Han	Deep-sea drillship	Part of the national drilling fleet
Oruç Reis	Seismic research vessel	Seismic surveys used to map subsurface structures
Barbaros Hayreddin Paşa	Seismic survey vessel	Seismic surveys in Turkish-claimed and licensed areas

The eight wells

Turkish official materials name eight major Eastern Mediterranean wells. The table lists them with the origin of each name. Exact coordinates, dates and the vessel used at each site should be taken from Ministry of Energy and TPAO announcements, not from secondary summaries.

Well	Name derives from
Alanya-1	Alanya, a coastal district of Antalya province
Finike-1	Finike, a coastal district of Antalya province
Karpaz-1	Karpaz (Karpas) Peninsula, Cyprus
Güzelyurt-1	Güzelyurt (Morphou), Cyprus
Mağusa-1	Mağusa (Famagusta), Cyprus
Narlıkuyu-1	Narlıkuyu, on the Mersin coast
Lefkoşa-1	Lefkoşa (Nicosia), Cyprus
Selçuklu-1	The Seljuk dynasty

What activity within declared limits means legally

Under the law of the sea, coastal states hold sovereign rights over the continental shelf for exploring and exploiting natural resources (UNCLOS Articles 77 and 56 reflect customary law, which Türkiye accepts even though it is not a party to the Convention). Where coasts are opposite or adjacent, delimitation must be effected by agreement “in order to achieve an equitable solution” (Articles 74 and 83 of UNCLOS; the equity principle also appears in ICJ cases such as the 1969 North Sea Continental Shelf judgment).

Drilling and surveying inside limits a state has declared and notified demonstrates consistent, public assertion of those claims. It also builds a record of exercised authority. Courts, however, have been cautious. In delimitation cases, tribunals such as the ICJ have generally treated unilateral oil concession practice as relevant only in limited circumstances, such as evidence of a tacit agreement. Activity therefore supports a claim but does not substitute for a boundary agreement or a ruling. Ankara's approach is to combine activity with filings, bilateral treaties and equity arguments.

Key Players & Positions

Greek Cypriot Administration (GCASC)

The Greek Cypriot side, represented as the Republic of Cyprus, says it exercises sovereign rights over an EEZ declared under its 2004 legislation and delimited with Egypt, Lebanon and Israel. It is a party to UNCLOS and has licensed offshore blocks to international energy companies. Its foreign ministry describes Turkish drilling and survey activity within those blocks as violations of its sovereign rights and of international law. It also denies that Turkish Cypriots hold separate offshore rights, arguing that resources belong to the Republic and that the Turkish Cypriot community would share in them as part of a settlement.

Greece

Greece's foreign ministry holds that islands generate a full continental shelf and EEZ under UNCLOS and customary law, citing Article 121. It sees Turkish activity and the Türkiye–Libya MoU of 2019 as disregarding the maritime zones of Crete, Kastellorizo and other islands. It also says the only dispute to resolve is delimitation of the continental shelf and EEZ, which it proposes to take to the International Court of Justice. Greece has signed its own partial EEZ delimitation with Egypt (2020).

European Union

The European Council has repeatedly called Turkish drilling in areas claimed by Cyprus “illegal” in its conclusions and expressed solidarity with Cyprus and Greece. In November 2019 the Council adopted a framework for restrictive measures over unauthorised drilling, and in 2020 it listed two TPAO officials under it. The EU treats Cyprus's EEZ as part of the Union's external maritime space.

Turkish Cypriots and the TRNC

The TRNC has issued licences to TPAO and states that Turkish Cypriots, as co-founders of the 1960 Republic, hold equal rights over the island's offshore resources. The Cyprus constitutional background is covered in Cyprus Papers and UNSC Resolution 186 (1964).

Other coastal states

Egypt, Israel and Lebanon are the other main coastal parties. The Seville Map, a Greek-supported depiction of maritime zones that Türkiye rejects, is explained in Regional Balance: What Is the Seville Map and Why Does Türkiye Reject It?.

Türkiye's Legal and Documentary Position

Türkiye's Legal and Documentary Position (as stated by Turkish government sources)

• Equity and the longest coast. According to the Turkish Foreign Ministry, maritime areas in the Eastern Mediterranean must be delimited on the basis of the principle of equity, coastal geography and proportionality. Ankara argues that islands cannot cut off the coastal projection of a mainland with the longest coastline in the region (about 870 km). The legal basis it cites is delimitation case law, including the ICJ's 1969 North Sea judgment, and it filed continental shelf coordinates with the UN from 2004 and the outer limits on 18 March 2020.
• Equal rights of Turkish Cypriots. Ankara states that Turkish Cypriots, as co-founders and equal partners in Cyprus under the 1959–1960 agreements and the 1960 Treaty of Guarantee, hold equal and inherent rights over offshore hydrocarbons, and that the Greek Cypriot side cannot decide on resources unilaterally. The 21 September 2011 Türkiye–TRNC delimitation agreement and TPAO's 2009 and 2012 licences are presented as the documentary expression of those rights.
• Revenue-sharing proposals. The TRNC put forward hydrocarbon cooperation and revenue-sharing proposals in 2011, 2012 and 2019, including a joint committee. Turkish officials say they remain on the table and that the issue can be settled without prejudice to the broader Cyprus question.
• Inclusive regional table. President Erdoğan's 2020 proposal for an Eastern Mediterranean Conference would bring together all coastal states and the Turkish Cypriots. Ankara's stated aim is a framework in which no energy arrangement is built without Türkiye and the TRNC. See The Worldlogue on the conference proposal.
• Field activity and institutional record. Ankara regards its drillships and seismic vessels as exercising sovereign rights within its declared limits. It has added institutional steps, including the Marine Spatial Planning unveiled on 16 April 2025 and recorded with IOC-UNESCO on 12 June 2025. Ankara also rejects the EU's competence to adjudicate maritime boundary disputes and the Seville Map. Its legal reading of UNCLOS is set out in The Nations Compass fact check.

The wider Blue Homeland concept is explained in Crossroads Review's maritime jurisdiction guide.

Source Comparison

The same events are described differently depending on whose documents one reads. The table separates the framing.

Issue	Greek Cypriot / Greek / EU documents	Turkish official documents
Wells and surveys	“Unauthorised” or “illegal” activity in Cypriot or Greek jurisdiction	Exercise of sovereign rights on Turkish and TRNC-licensed continental shelf
Legal basis	UNCLOS, Cyprus's 2004 EEZ law, bilateral EEZ agreements, EU law	Principle of equity, 1960 treaties, TRNC licences, UN filings of 2004 and 2020
Role of islands	Islands generate full maritime zones	Islands cannot cut off a mainland's coastal projection
Turkish Cypriots	Share in resources via a settlement	Hold equal, inherent rights now
Remedy	ICJ delimitation, restrictive measures	Regional conference, joint committee, bilateral agreements

When comparing sources, readers should check four things. First, whether a text is a treaty, a national law or a political statement. Second, whether coordinates are published. Third, whether a document records a state's own claim or a third party's acceptance of it. Fourth, how each source characterises the status of the Turkish Cypriots. Editorial Principles explains how this site labels each type of source.

Key Terms & Related Guides

• TPAO: Türkiye Petrolleri Anonim Ortaklığı, the Turkish state petroleum company that holds the licences.
• Continental shelf: The seabed and subsoil over which a coastal state exercises sovereign rights for resource exploitation.
• EEZ: Exclusive Economic Zone, extending up to 200 nautical miles from baselines, where delimitation is required between overlapping claims.
• GCASC: Greek Cypriot Administration of Southern Cyprus, the term used in Türkiye's official terminology for the administration that is internationally referred to as the Republic of Cyprus.
• TRNC: Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983 and recognised only by Türkiye.
• Effectivités: Acts of authority actually exercised in an area, which tribunals treat as secondary to treaties and equity in most delimitation cases.

Related reading: Text & Territory home, Primary Document Library and Index of Nations on Blue Homeland. Method questions are answered in the FAQ.

Perspective Note

Text & Territory presents Türkiye's official perspective on the issues covered and explicitly distinguishes between that perspective and independent commentary. All claims are anchored in primary sources such as treaty texts, UN documents, archival records and official statements, which are cited so that readers can verify them. Sections marked “Türkiye's Legal and Documentary Position” reflect official Turkish policy as stated by Turkish government sources.