Overview of current licenses and fields
The history of petroleum exploration in Mozambique may be divided into five phases:
1927 to 1937. Although a few shallow wells were drilled on reported surface oil seeps in Inhambane province earlier, significant exploration commenced with the drilling of seven wells on the Inhaminga Uplift (Lower Zambezi Graben) to 500 - 2,000 m. One well (Inh-5) was a gas blow out.
1948 to 1972. Several concessions were awarded during the post-war late colonial period, initially to Gulf Oil, who drilled 40 onshore E and A wells on the Mozambique Plain from 1953 and the first offshore well (Nemo-1X) in 1969. Eleven further offshore wells, in water depths from 11 to 63 m, included the first two on the Zambezi Delta drilled by Hunt in 1971. This period resulted in several significant gas discoveries on the Pande-Temane High (Temane, Pande, Buzi and Inhasorro) although, with no appropriate market, these were considered non-commercial.
1973 to 1980. With increased civil unrest leading up to independence in 1975, Hunt withdrew from their concession in 1973. No exploration activity took place until the end of the Civil War and establishment of a stable government.
1981 to 2004. Following enactment of the first Petroleum Law in 1981, Empresa Nacional de Hidrocarbonetos (ENH) was formed and commissioned two large offshore speculative 2D surveys by Western and Geco (24,100 km) in 1981/82. This was followed by the award of new concessions in the onshore Rovuma (Shell) and offshore Zambezi (Amoco / BP), with BP taking a seismic option in the Xai-Xai Graben.
Esso drilled the first well in the Rovuma Basin, onshore with the Mocimboa-1 well (1986), with gas shows in Albian sands and BP drilled Xai-Xai-1 in 1988. Extensive drilling, initially by ENH and then Arco and Sasol, confirmed commercial gas reserves at Temane, Pande and Inhassoro (with associated light oil proved in 2003). Temane was placed on production in 2004, with gas exported to Secunda (South Africa).
2005 to 2021. Following enactment of a revised Petroleum Law (2001), Mozambique’s first two formal licence rounds focused on the Zambezi Delta (2001) and the onshore / offshore Rovuma (2005). Seven blocks awarded in 2006 to Anadarko, ENI, Petronas and Hydro (Statoil) and to Artumas (Wentworth) onshore, covered almost the entire Rovuma Basin area. The committed total minimum spend was $314 million, including nine firm wells and extensive 3D and 2D seismic acquisition and reprocessing. From 2010 to 2015, thirty exploration and 32 appraisal wells proved major gas reserves in Paleocene to Oligocene deep-water fan sands. The Coral Sud Field is under development, with production anticipated in 2022.
Exploration blocks awarded in the 5th Round (2018) included the first in the Angoche Sub-Basin (to ExxonMobil and ENI), two blocks on the Beira High off the Zambezi Delta (ExxonMobil), and an onshore block between Pande and Temane (Sasol). Sasol placed the Pande Field on production in 2009, with development of the gas and oil reserves on Inhassoro planned.
Mozambique has a resource estimated at 125 TCF of proven gas in the Rovuma Basin (Areas 1 and 4), mainly in Paleocene to Oligocene deep-water fan sandstones. In the producing Pande and Temane fields and the undeveloped Inhassoro Field, initial gas reserves were 5.15 TCF in Upper Cretaceous marine shelf sandstones, plus 130 mmbbl of light oil in Inhassoro.
Although approximately fifty offshore exploration wells have been drilled in Mozambique, large basinal areas remain undrilled, with no wells in the Angoche Basin, and drilling limited in the Zambezi / Beira High area to a few wells on Tertiary delta plays. Extensive 2D and 3D seismic data sets demonstrate high potential in these areas, and in the Rovuma Basin flanking the main delta depocentre and the offshore extension of the Mozambique Plain, with proven high-quality reservoirs in the Cretaceous and throughout the Tertiary section.
Although Mozambique’s resources are dominated by gas and condensate, there is widespread evidence for the development of an oil-prone petroleum system. This includes the Inhassoro oil accumulations, migrant oil in the Ironclad-1 well in the Rovuma Basin and coastal oil seeps in the southern Rovuma, Angoche and Palmeiras basins. A likely source for the proven gas / condensate and oil is the Lower Cretaceous (Aptian) Lower Domo Shale, although older syn-rift (Triassic to Middle Jurassic) lacustrine and marine black shales have been typed to some seeps and additional potential has been recognised in marine Neocomian and Upper Jurassic shales. These source candidates would be oil-mature on the flanks of the major Rovuma and Zambezi depocentres.