Our assets in
São Tomé and Príncipe


Exclusive Economic Zone (EEZ)

OER holds its interest in Blocks 5 and 12 through its 81.5% interest in EEL. In February 2010, in accordance with agreements signed in 2001 and 2003, the government of STP awarded OER Blocks 5 and 12, located within the country’s EEZ. Block 5 has an area of 2,844 km2 and the water depth within the block ranges from 2000 to 2500 m. Existing 2D seismic data over the block were reprocessed in 2014 and interpreted to identify several prospects. In 2015, 3D seismic data was acquired over an area of 1400 km2. The processing of the newly acquired 3D seismic data was completed in December 2015 and interpretation of the 3D is currently ongoing to further mature identified prospects for exploration drilling in 2017.




EEZ Blocks 5 & 12*


Working interest 100%
Operator Equator Exploration Limited
Work programme Exploration

* EEZ 12 PSC negotiation ongoing.


In December 2015, EEL agreed to farm out 65% of its participating interest in Block 5 for $7.4 million to equalize past costs and will retain a 20% participating interest, with a 50% carry up to $9.0 million each for both Phases II and III. EEL also entered into an agreement to farm out 65% of its participating interest in Block 12, retaining a 22.5% participating interest with a carry of the first $2.0 million of OER’s portion of project costs. The farm-out for Block 12 is yet to be completed. The government of STP (through its national petroleum agency) will retain 15% and 12.5% carried interests in Blocks 5 and 12, respectively. 

The maritime boundaries of São Tomé & Príncipe encompass an area of approximately 160,000 square kilometers. The close proximity of São Tomé & Príncipe’s offshore waters to the proven hydrocarbon systems in the adjacent waters of Nigeria, Cameroon, Equatorial Guinea and Gabon suggests the potential for hydrocarbons, which is further supported by regional seismic data and petroleum seeps seen on the islands.


The Production Sharing Contract (‘PSC’) for Block 5 was executed with the National Petroleum Agency of São Tomé & Príncipe on the 18 April 2012. With the exception of the level of carried participation for the government, the terms of the PSC for Block 12 have been agreed.

Both assets are offshore deep-water, depth ranging between 2,000m and 3000m with acreage sizes 2,844 and 7,939 km² for Block 5 and 12 respectively.

Block 5 has an area of 2,844 sq km (three times the size of Nigerian 2005 deepwater blocks) and is located east of the island of Príncipe, adjacent to the Equatorial Guinean shelf with water depths ranging from 2000 to 2500m. The block is within Zone A of the ANP block classification scheme. There are no wells in the EEZ.  Within Block 5, there are approximately 1500 km of 2D Seismic data on a wide spacing of about 2.5km by 5km. Seven main seismic horizons at Basement, Albian, Campanian, Top Cretaceous, Mid Eocene, Neogene and Seabed were mapped in time and depth across the block.  Numerous prospects are identified, predominantly associated with structural trapping geometries over the Kribi fracture zone.  

Closures in the Mesozioc section from the Albian through to the Upper Cretaceous are considered prospective. Further opportunities exist within stratigraphic plays in the Upper Cretaceous and potentially the Tertiary.

Block 12 has an area of 7939sq km and is located in the south east side of the island of Sao Tome, adjacent to the Gabon shelf with water depth ranging from 2000 to 3000m. The block is within the Zone B of the ANP block classification scheme. There are no wells within the EEZ. Within block 12, there are approximately 988km of good quality 2D line data on a wide spacing of 2.5km by 5km. The PSC for Block 12 is still under negotiation.


Recent Developments:

The Company continued to seek farmout partners in order to manage the exposure to the risks of high cost exploration in a frontier province in ultra-deep water. A number of companies visited the data room in order to assess the opportunity and some have expressed interest. 

Following the signing of the Production Sharing Contract (‘PSC’) for Block 5 with the National Petroleum Agency of São Tomé & Príncipe on the 18 April 2012, a signature bonus of US$ 2million was paid. A performance bond of $5.2 m was submitted to the National Petroleum Agency in February 2014 in line with the minimum work commitment for phase 1 work program.

The 2014 activities were geared towards delineating the information available in order to ascertain the optimal location to acquire 3D seismic data. Over 1,700 km of existing 2D seismic data was reprocessed & reinterpreted together with the magnetic & gravity data available on the license area. The EIA for seismic activities was also delivered in 2014. 

In 2015, approval to acquire 3D seismic over the license area was given by the ANP-STP. Equator acquired 1,400 sq. km of 3D seismic data through an ingenious risk sharing agreement with Geoex & BGP. All Data acquired are currently being delivered to the processing center.