Prinos Concession

Prinos Concession Pop Up

Energean is the Operator in the Prinos licence,  Northern Greece, where has a 100 per cent working interest. Prinos North and Epsilon are currently the only producing fields in Greece.

Prinos North and Epsilon oil fields are located in the Gulf of Kavala, 18 km south of the mainland of Northern Greece, in water depth of 30 to 38 metres. 


40 mmboe 2P reserves
55 mmboe 2C resources

Since 2015, Energean has successfully drilled ten wells in the fields of the Prinos Concession with its privately owned drilling rig "Energean Force", including two ERDs. Prior to that (2009-2015), Energean mobilised four jack ups which successfully drilled five wells.

The Company managed to increase 2P reserves to 40 mmboe from just 2 mmboe in 2007. Prinos also has 55 mmboe 2C resources.

Cumulative production stands approximately at 117 million barrels of oil.

In late 2019, Energean decided to place the Prinos area assets under strategic review.


In 2019, Energean drilled successfully three development wells in Epsilon oil field. Additional pay was encountered in the deeper and dolomitic zones of the Epsilon reservoir. This resulted in an NSAI-audited reserve and contingent resource increase of 26 MMboe, to 44 mmboe.

Due to the conditions in the market, Energean has placed the Epsilon Development project, including the construction of the unmanned Lamda platform, on hold. 






Following exploration of the Prinos Basin in the 1970s, the Prinos Field was discovered in 1974 through the drilling of Prinos-1, the first exploration well drilled in the area. It was developed during the late 1970s and brought into production in 1981.

The initial development of the field took place from 1979 until 1981, following the drilling of the delineation wells which confirmed the extent of the Prinos reservoir,. Facilities were installed offshore and onshore to allow 30,000 bopd to be produced along with associated gas. Two drilling jackets were installed above the Prinos Field and bridge linked to an unmanned offshore processing platform. Via a pipeline, these offshore facilities were linked by pipeline to the shore, where a complex gas and oil processing plant was constructed along with oil storage tanks (500,000 bbl capacity) and offshore loading terminal.

Crude oil production commenced in early 1981, at initial rates of 8,000 to 10,000 bopd, with production peaking at more than 27,000 bopd in 1985. Prinos 2P reserves were initially estimated at 60 million oil bbls, but the field has already produced more than 110 million bbls since 1981.

Prinos North

The Prinos North structure was initially identified as a potential exploration opportunity in 1976, when the Prinos-4 (P-4) delineation well encountered small quantities of oil to the north of the Prinos Oil Field.

Prinos North was appraised and developed as a satellite field to Prinos by an extended reach horizontal well, PNA-H1, in 1996. The following year, PNA-H1 was brought in production and produced until 2004 at an initial rate of 3,000 bbls/d with an interruption during the period 1998-1999, when a decline set in due to water breakthrough.

An extended reach well, PNA-H3, was successfully drilled by Energean in 2009, through a challenging operation due to the geological complexity of the target reservoir. The well reached a total depth of 4,370 metres, with a 358metre horizontal section into the reservoir.


Exploration activity in the Epsilon Field area began in the 1990s, when the anticlinic Epsilon structure was identified by the interpretation of 2D seismic data. The area remained a low priority, and was only partially covered by the 1993 3D seismic cube. The 3D seismic survey conducted  in 1997, however, covered the whole area and made it possible to map the structure, and consequently upgrade Epsilon as a high priority exploration target.

The field was discovered in 2000 when Well E-1 tested sour crude oil with an API gravity of 36 degrees in reservoirs belonging to the Prinos Group at a depth of about 2,800 metres TVDSS.  The well was side-tracked a year later to a location some 500 metere to the south-east, confirming the reservoir presence and tested oil.

Energean drilled an extended reach multi-lateral well, EA-H1, which was  completed in January 2010 and produced over 0.3 mmbbls of oil over a 12-month period. The length of the well reached 5,297 metres, with more than 450 metres horizontal section of each leg, making it the longest well in the Mediterranean to date.

The 2015 Seismic Survey

Energean conducted a 340 km2 broadband 3D seismic survey over the Prinos Oil Field and its surrounding licences in the Gulf of Kavala during the summer of 2015. The survey al;so included a complex undershooting operation in the vincinity of the Prinos offshore platform.

The 3D seismic survey acquired in 2015 was processed by Down Under Geosolutions (DUG) in 2016 using the PSTM processing workflow. The interpretation of the seismic data was critical in updating the Prinos field  static model and the identification of remaining oil. 

Consequently the optimal placement of infill wells resulted in the improved depletion of the Prinos Field. The 3D seismic volume was important in refining the placement of the PNA-H4 Prinos North well.

The Epsilon filed static model was also updated in order to assist in the design of the producing wells and the optimum positioning of the Epsilon offshore facilities.  The successful well depth prognosis for the vertical wells and the horizontal EA-H3  wells showed the value of the better quality 3D velocity model and the increased resolution of the encountered seismic reflectors resulting from the PSDM re-processing.

In July 2018, Energean discovered oil pay intervals in the deeper Kazaviti and D horizons in the PA-32 well. Based on well logs, both reservoir units were predicted to be of low permeability and discrete well tests were unable to establish a flow to surface. Oil was subsequently seen and sampled at the PA-32 wellhead immediately prior to perforating operations on the shallower B-reservoir.