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West Equatorial AfricaSPAN

West Equatorial AfricaSPAN is a new 2D Multi-Client program offshore Ghana with 5,450 km of new long offset, long record length 2D seismic data, with the option to extend up to a total of 7,200 km. Ghana is an emerging area with significant potential, and this industry funded program is part of a major regional framework of data that ION has proposed across the Equatorial Africa area.

Ghana has announced its first 2018 competitive bid round across the offshore Accra-Keta Basin with ION acquisition planned to be complete May 2018, and fast track products available in Q3 2018.

Commercial

Ghana is a well-known player in the West Africa oil and gas sector. With new projects coming online and a stable geopolitical climate, Ghana presents an attractive business environment for long-term investment. Ongoing exploration since initial major discoveries has led to eight deepwater and ultra-deepwater discoveries in Ghana over the past five years.

Jubilee is currently Ghana’s largest oil field, with recoverable reserves amounting to 1.2 billion barrels of oil. It has now reached production levels of 120,000 barrels per day, with plans for a future production increase to 150,000-160,000 barrels per day. The nearby TEN complex of fields also started production in 2016.

Geological

Ghana is a party of the Gulf of Guinea Province, formed in the Early Cretaceous as a result of transform faulting between Africa and South America, eventually leading to a break-up. Generally three phases are defined: 1. Pre-transform (Late Proterozoic to Late Jurassic), 2. Syn-transform, including rifting and compressional events (Early Cretaceous) and 3. Post-transform (Late Cretaceous to Holocene).

Successes within the province have included two main types:

  • Syn-rift plays of the Lower Cretaceous with reservoirs in Barremian to Albian aged clastics mainly restricted to the shelfal areas and sourced from Aptian and older shale units.
  • Post-rift slope and basin floor fan complexes with clastic turbidite reservoirs of mainly Late Cretaceous age, largely sourced by the regional Cenomanian/Turonian shales.

The Jubilee field, discovered in 2007, is the largest discovery to date in this play, and is a combination structural stratigraphic trap in Turonian turbidites. Since the discovery of Jubilee, the Late Cretaceous fan play has been extensively explored along the West African margin with limited success. The key to de-risking the play lies in the maturity and charge model, requiring an understanding of the distribution and burial/thermal history of the key source intervals and the geometry of the basin which will define the charge focusing. The West Equatorial AfricaSPAN survey was designed with the objective of fully understanding the history of the margin from break-up to the present day in terms of geometric configuration as well as tectonostratigraphic development.

Line orientations have been defined that will capture both the rift and transform and later compressional events previously recognized on the margin. These images will provide invaluable input into the tectonic models. The long record lengths will allow for an image of the full crustal section in order to understand the crustal architecture and extent of the continental crust, as well as the exact nature of the crustal boundaries along rift and transform sections of the margin, providing additional constraints to thermal models.

Key Components

  • With over 145,500 km offshore Africa, ION brings extensive imaging experience to utilize the appropriate technologies from our broad toolkit to this equatorial program
  • Deep tow acquisition and broadband processing to enable superior deep imaging
  • Fast track products to be delivered in Q3 2018 with final products planned for Q1 2019

Acknowledgements

  • The West Equatorial AfricaSPAN Program was developed in partnership between ION, Geoex and Ghana Geophysical with support from the Petroleum Commission, Ghana