ERHC Energy Inc (ERHE)

[seek the light]

oldoil.....Here is what i found: 2015 to Present Day – Continued Awards and Revived Exploration:

This is the most exciting period of exploration for the STP-EEZ, initiated by the award of Block 6 to Galp Energia in 2015, an agreement that included a 45% stake for Kosmos Energy, who earlier that year had farmed-in to Equator Explorations Block 12. Kosmos Energy then expanded its block licence footprint in 2017 by farming-in to Block 5, taking over the operatorship from Equator Exploration, followed a year later by their farm-in to Block 11, to take over all licence rights from ERHC. The latter agreement saw Kosmos partner with Galp Energia, with whom they already held a partnership in neighbouring Block 6. In 2018 Kosmos Energy completed its most recent activities by licensing, together with BP, Blocks 10 and 13 before the acquisition of extensive 3D seismic surveys with a focus over the eastern blocks.

Why São Tomé and Príncipe is a Hot Oil and Gas Exploration Area
The PGS MultiClient data library over the region now includes the 2D survey acquired for ExxonMobil in 1999, together with the later 2D seismic, gravity and magnetic surveys acquired by PGS in 2001 and 2005. These three surveys have recently been reprocessed as a coherent dataset to allow seamless interpretation. In addition, the PGS MultiClient library contains the well data from Ubabudo-1 together with the eight exploration wells and one appraisal well drilled in the JDZ waters.

The interpretation of these data along with industry feedback have indicated that there are four key reasons for the recent interest in the area.

Four Key Reasons to be Excited About the Hydrocarbon Potential in the STP-EEZ
Reason 1: Continental and Transitional Crust Provides Source and Structure
Historic geological interpretations predicted that the waters of the southern Gulf of Guinea, including the Niger Delta, were underpinned by oceanic crust. Revised crustal observations and models now suggest these areas instead contain a mélange of continental, transitional and oceanic crustal types controlled by extensional then compressional transform fracture zones. These revised crustal models have highlighted the potential for syn-kinematic sediments deposited in restricted marine conditions that can provide source rock deposits and accompanying structural plays.

Reason 2: PGS Basin Modelling Suggests Cretaceous Sediment Fill Mature for Oil

Source rock basin modelling results showing vitrinite reflectance, indicating source rock maturity.
PGS have recently conducted a basin modelling study based on these revised continental and transitional crustal models. Temperature and source rock data from wells within the JDZ and offshore Gabon were also included. The study modelled three pseudowell locations in STP-EEZ to test the maturities of both the early post-kinematic sediments (Cenomanian-Turonian) and syn-kinematic source rocks. The results show that both potential source rocks are mature for oil and gas and are able to have charged the multiple sandstone reservoirs of the thick Cretaceous and Tertiary clastic successions. These results appear complementary to the presence of oil seeps onshore northern São Tomé at Uba Budo that have been typed to a Cretaceous source rock (ANP-STP).

Reason 3: Long-Lived Fluvial Systems Provide Thick Clastic Reservoir-Quality Successions
The Gulf of Guinea forms the sink for numerous fluvial systems: to the north lies the Niger Delta whilst to the northeast the Cross and Sanga River systems feed the Douala and Rio del Rey basins of Cameroon. To the south-east lies the Rio Muni Basin fed by the Mbini River of Equatorial Guinea and the Ogooué River of north Gabon. These rivers are believed to be long-lived, evident from Cretaceous sections interpreted on seismic data. The influence of these fluvial systems is witnessed by the preservation of unusually thick successions of distal fluvial outflow sediments with differing provenances and varying points of sediment input.

Reason 4: New Sub-Akata Shale plays in the Distal Parts of the Niger Delta

An arbitrary line through Nigeria and the JDZ showing the sub-Akata Shale synkinematic structure and stratigraphy. The potential for a sub-Akata petroleum system has excited Niger Delta explorers and operators.
The prolific plays of the Niger Delta are encountered in Tertiary siliciclastic reservoirs that are charged by the Eocene Akata Shale source rock. An exciting new play concept, which has captured the recent attention of operators and explorers, lies beneath the Akata sedimentary succession of the distal or outboard parts of the Niger Delta. Here, a thinned Tertiary succession lies atop continental or transitional crusts. This play, as yet untested, predicts that the syn-kinematic source rocks are mature for oil and charge clastic reservoirs beneath the Akata Shale that acts as a seal rock. This new Niger Delta play is interpreted to continue southwards into the outboard Gulf of Guinea, including the STP-EEZ and the deep waters of Gabon.

Oil and Gas Potential in the STP-EEZ Revealed
The surge in activity would appear to be a consequence of changes in geological understanding rather than for sociopolitical reasons. Modern processing of vintage seismic has provided compelling evidence that the crust beneath the STP-EEZ is a melange of continental, transitional and oceanic types influenced by transform tectonism. The overlying sedimentary wedges that fill the associated kinematic basins have the appearance of isolated basins. When these syn-kinematic sediments are applied to basin models, the results suggest that they are mature for oil and gas, results that are supported by the presence of hydrocarbon seeps onshore São Tomé Island. The post-kinematic stratigraphy is dominated by multiple long-lived fluvial systems that likely provide reservoir quality sand bodies that onlap and drape the transform structures providing structural and stratigraphic traps.

All the elements of a working petroleum system appear to be present in the waters of the STP-EEZ. As exploration advances and wells are planned, it may only be a matter of time before we see the fruits that these new play concepts may bear.

References:
Basedau, M. & Mehler, A. (eds.) Resource Politics in Sub-Saharan Africa. Hamburg African Studies, Institute for African Affairs, 2005

https://www.geoexpro.com/articles/2018/12/sao-tome-and-principe-exclusive-economic-zone