Glaucus & Pegasus
Resource Potential
Much of the uncertainty has now been resolved. The Pegasus discovery of July 2025 added a second field to Block 10, and on 30 June 2026 Cyprus, ExxonMobil and QatarEnergy declared Glaucus and Pegasus commercial. The declaration stated no combined figure, and no document does: what has been published is set out below, with each source. Pegasus itself has yet to be fully quantified, with appraisal drilling planned for end-2026. Remaining upside lies in untested prospects and adjacent acreage.
Updated October 2026 · Sources: MECI, ExxonMobil, press reports
Resource Scenarios
What has been published about the volume
documents first, newest first — these do not all agreeThe "7-9 tcf combined" figure cited at the June 2026 Declaration of Commercial Discovery (the September 2025 government confirmation had said 8-9 tcf) is in no document: it is an envelope around two spoken remarks about Glaucus and Pegasus together. The ministry's own written estimate, after the Glaucus-2 appraisal well, is 3.7 tcf for Glaucus alone — Pegasus, not yet fully quantified, has no published figure of its own.
- 3.7 TcfGas in placeDocument2022Glaucus alone, the ministry’s best estimate after the Glaucus-2 appraisal wellStated in Cyprus MECI Hydrocarbons Serviceprimary
- 5–8 tcfGas in placeDocument2019-02-28Glaucus-1 alone, on preliminary interpretation of the well data, before any appraisal wellStated in ExxonMobil, Glaucus-1 discovery releaseprimary
- ~7 tcfAs reportedRelayed remark2026-04-03Glaucus and Pegasus combinedRelayed by Cyprus energy minister Michalis Damianos, press conference — Cyprus Mail
- 8–9 tcfAs reportedRelayed remark2025-09-25Glaucus and Pegasus combined. The report says "ExxonMobil officials told President Nikos Christodoulides" that the blocks "may contain as much as 8-9 trillion cubic feet", and names vice president John Ardill as heading the delegation — so the figure is the company’s and attributing the sentence to him personally would be an inferenceRelayed by ExxonMobil, to the President of Cyprus in New York — relayed by the President and the energy minister, via the Cyprus Mail
Exploration Upside
ExxonMobil will reprocess seismic over Blocks 4 and the new "10A" designation before deciding whether to drill. Energy Minister Michael Damianos has also flagged a possible new licensing round within 1-2 years. Further prospects remain untested.
What Could Add Volume?
New Acreage (Blocks 4 & 10A)
ExxonMobil will reprocess seismic over Blocks 4 and "10A" before deciding on drilling
UnquantifiedDeeper Reservoirs
Untested deeper zones may contain additional gas accumulations
UntestedProven Play Extension
Pegasus (~350m gas column) confirmed the play concept works beyond the original Glaucus structure
De-risks nearby prospectsBetter Recovery
High-quality reservoirs could support strong recovery factors
Development-dependentRegional Comparison
| Field | Country | Reserves | Status |
|---|---|---|---|
| Zohr | Egypt | 30 Tcf | Producing |
| Leviathan | Israel | 22.9 Tcf | Producing |
| Glaucus + Pegasus | Cyprus | 7-9 Tcf As reported Relayed remark | Development |
| Tamar | Israel | 10 Tcf | Producing |
| Aphrodite | Cyprus | ~3.7 Tcf | Development |
The Glaucus and Pegasus row is marked as reported: 7-9 Tcf for the two fields combined is in no document, and the rows above and below it are reserves of fields already in production. The ministry's own written estimate, for Glaucus alone, is 3.7 Tcf.
Updated October 2026 · Sources: Operator disclosures, government statements
Path to Development
With commerciality declared, Block 10 has entered the development phase. Key milestones and open questions:
Pegasus Discovery (July 2025)
Drilled by the Valaris DS-9; roughly 350m gas column, 190km southwest of Cyprus in 1,921m of water.
Commerciality Declaration (30 June 2026)
Cyprus, ExxonMobil and QatarEnergy signed the Offshore Cyprus Declaration of Commercial Discovery in Nicosia, moving Glaucus and Pegasus into the development phase.
Pegasus Appraisal (end-2026)
A rig is under contract with delivery expected around December 2026; wells are being designed and permitted. Appraisal drilling will feed into FEED.
Development Concept (open)
The leading concept is a subsea pipeline into Egypt's existing LNG infrastructure; FLNG and onshore LNG remain alternatives, though onshore would require more resource than currently discovered.
FID ~2029, Production ~2033
Timeline indicated by ExxonMobil VP John Ardill at the June 2026 declaration ceremony.
Why No Capex or Revenue Scenario Is Published for the As Reported 7-9 Tcf
Because the as reported 7-9 tcf is an envelope around two spoken remarks rather than a stated volume, no gross field value or government-revenue range is computed from it here. The ministry's written estimate, for Glaucus alone, is 3.7 Tcf.
Glaucus in the News
ExxonMobil’s East Med strategy enters a new phase
The Commerciality Declaration for Cyprus’ Glaucus and Pegasus gas discoveries made this week marks an important milestone – not only for the island, but also for ExxonMobil’s wider Eastern Mediterranean strategy. After almost eight years of exploration, the company has formally moved from proving...
The landscape is changing in Cyprus’ exclusive economic zone
The Republic of Cyprus, ExxonMobil and QatarEnergy recently signed a tradability statement for the Glaucus and Pegasus gas fields. This marks a significant step forward in Cyprus’ energy programme. It is clear evidence — a vote of confidence — in the prospects of Cyprus’ exclusive economic zone, ...
ExxonMobil eyes 2033 production start at Cyprus gas fields
Cyprus, ExxonMobil and QatarEnergy have signed a declaration of commerciality for the Glaucus and Pegasus natural gas fields, moving the discoveries from the exploration phase into development. President Nikos Christodoulides described the move as a “milestone of strategic importance” for Cyprus’...
QatarEnergy, ExxonMobil Declare Cyprus Gas Discoveries Commercial
QatarEnergy, ExxonMobil and the Government of Cyprus have signed a commercial discovery declaration for the Glaucus and Pegasus fields in Block 10 offshore Cyprus…
Cypriot gas fields declared ‘marketable’ by energy giants
Two gas fields located in Cyprus exclusive economic zone (EEZ) were on Tuesday declared “marketable” by multinational energy corporations ExxonMobil and QatarEnergy. Both fields, the ‘Pegasus’ field and the ‘Glaucus’ field, are located in Block 10 of Cyprus’ EEZ, with ExxonMobil and QatarEnergy h...