The petroleum and natural gas potential of Ghana

The research was conducted to determine the Petroleum and Natural Gas Potential of Ghana using secondary data sources. One of the aims of the research was to determine the role of plate tectonics and the opening of the South Atlantic Ocean played in the accumulation of petroleum and natural gas in the Gulf of Guinea in general and Ghana in particular. The research was conducted using systematic review approach of qualitative research method. The data sources used in this study were focused on peer-reviewed journals, conference articles, books, thesis works, reports and other sources relevant to this study. The results of the study show that Ghana has four sedimentary basins, one inland (Voltaian) and three offshore basins (Tano, Saltpond, and Keta). The Tano basin has source rock of Cenomanian, Turonian and Albian ages which serves as the major plays in the Tano Basin. The reservoir sands are of upper Cretaceous times making the Turonian turbidite sandstones (slope fan) and Albian sandstones (tilted faults). The Albian shale series, Cenomanian shale series, and Turonian shale series serve as the seal plays in the Tano basin with the trapping mechanisms mainly both structural and stratigraphic as well as post-transitional anticlinal traps (fault-block). Major discoveries have been made in different parts of the Tano Basin. The first economical valued discovery in the Tano Basin was made in 2007 in the Jubilee field (Mahogany-1 discovery) which estimated to have recoverable reserves of 1.2 billion barrels of oil. The potential source rock in the Saltpond basin is the Devonian shales (Takoradi shales) and the main reservoir rocks of the Saltpond basin are the sandstones of the Takoradi sandstone formation which are of Devonian to Carboniferous of age. The Saltpond has both structural and stratigraphic trapping mechanisms with the reservoirs sealed by the Takoradi shale formation. The Saltpond is the second prolific basin which has been estimated to have a total reserve of about 7.5 million barrels of oil. The Keta basin has the Devonian shales, Lower Cretaceous shales and Late Cretaceous shales as the main source rocks and the reservoir rocks are of Albian, Late Cretaceous and Tertiary of age and the trapping mechanisms are both structural and stratigraphic. The Keta basin which is after the Saltpond basin has not proven to have any recoverable reserves due to less exploration work in it. The possible petroleum system known in the Voltaian is the Oti Group made of sandstones, shales, and siltstones. The Voltaian which is an inland basin has also