Petroleum Technical Review
The Equatorial Region Guinea is a part of the two world-class gasoline sediment basins. Both are very prospective for hydrocarbons with proven petroleum systems including sea oil-prone source rocks and high-quality sandstone reservoirs.
In the north of the country around Bioko, the offshore sector covered the distal parts of the Delta-Rio Del Rey Niger system. Delta Niger is one of the largest oil provinces in the world with estimates of oil reserves proven 48 billion BBLs. The equatorial part of the basin has established oil and gas production from Zafiro and Alba Fields plus a number of other inventions.
The southern part of the offshore equatorial guinea sector faces the Basin Rio Muni. It is adjacent to the Kribi-Campo (Douala) Cameroon basin (Douala) to the north (which organizes the oil and gas field and Santa Sud – Kribi) and with North Gabon basin to the south which contains many discoveries of oil and gas. The excellent potential of Basin Rio Muni has been shown by the discovery of commercial oil in the Ceiba field.
The sediment section is under the Bioko and Rio Muni region leaving the ocean to the Territorial Limit of the Equatorial Guinea. Sediment from the Delta Niger Distal Basin and those who deeply douua and Rio Muni Basins joined in the southern region of Bioko, providing significant petroleum potential for the entire equatorial coastal area.
The industry’s attention is now expanded to the Ultra-Deepwater Guinea Bay around the Cameroon volcanic trends that include the Island of Guinean Khatulistiwa Annobon. Here it is consoured that the extensive offshore economic zone can contain thick sediment parts with potential of petroleum, as evidenced by seeping oil on neighboring volcanic islands Sao Tome and Principe.
Geology of The Rio Muni Basin
Basin Rio Muni formed a part of a broad West African Margin Basin system, formed during the separation of the continent and the creation of South Atlantic Ocean through Cretaceous and Tertiary. This basin system contains massively cretaceous slices with tertiary sediments built on the initial Rifted Cretaceous Terrane.
In the northern baskom of Gabon and extending to Rio South Muni, the Rift section consists of lacustrine and fluvio-delta that blames and tilizes the barremian strata and the days of Neocomian. In Gabon this section includes a proven sandstone reservoir, and Kissasta and Melania Lacustrine Shales which is a productive source rock interval. On top of the SYN-Rift section is a thick part of late aptian salts and well-developed succession from the mid to end of the lime and limah sea tertiary and sand fragments. The movement of salt has formed various kinds of prospective traps including brothers, turtle backs, and rollover structures to growth errors on salt wall margins.
In the Northern Rio Muni, the Syn-Rift section consists of a final barremian into the mid-terrestrial appative and a series of lacustrine which is marked with an extensional roller structure to the Mega Updip electricity error, and the toe structure of downdips. The SYN-Rift section is trapped by the “transition” order of salt that is well developed and the bed interval of good quality sea oil sources. Albian (Madela) The carbonate platform developed above this area plus the sequence of cenomanian-turonian sand fragments containing the main source interval. This post-salt sequence usually forms an extensive raft regardless of flakes or albian-aptian salt. The senonian part was well developed twisted the previous raft topography. The latest drift sequence is dominated by thick miocene slices to clastic recently.
Modeling shows that “transition” source intervals may cook locally on the shelf and may have imposed Albian to carbonate and turon clastic. On the equivalent of water that is believed to have produced hydrocarbons from mid-tertiary time and giving the possibility of sources on deep water sandstone that provides a very good reservoir found in Ceiba.
Geology of Offshore Bioko
Bioko offshore contains an active petroleum system consisting of reservoir sand located structurally above the vast sea fragments containing oil-prone source rocks. The most important of this is the sea shales from the Basial PlioCene Qua-Iboe and the Miosen Formation AKATA (Isongo) which contains Kerogen type III and type III mixed.
The thick tertiary order to the sand and Shales quarter was deposited as a slices of a clastic sediment in the Delta Delta Delta settings. Sedimentation the edge of the shelf has caused the deposition of the slope of the delta and caracles basineal with various gravitational-driven processes including gravity sliding, debris flow and turbidity flow. Delta usage has been accompanied by dadirism of flakes and growth faults with relevant rollover structures, and the compression foot drive zone has developed at the foot of the Delta slope.
Reservoir in the Zafiro Field Complex occurred in the flow of debris and slumped sandstone from the QUA-IBOE formation, which consisted of large sand stored stored in the setting of water inside. The Alba field produces deep water sand in Isongo formation.
Simple four-way structural cover and toe-push structure is common in Isongo formation while the QUA IBOE formation contains a number of strategically enhanced stratigraphic traps. A good seal for all traps is provided by Qua-Iboe and Shales Isongo that are interdeded.
The regional seismic line shows that the midroisous strata to the end is far further into ultra-deep water and of course under volcanic intrussic today such as Bioko Island. This is evidenced by seeping oil on volcanic trends in Sao Tome and the occurrence of Turon amatches in Bioko. The volcanic presence in this arrangement is therefore no need to block the incidence of hydrocarbons around Bioko and other islands in the chain, including Annobon.
Exploration is at an immature stage in Bijoko offshore and has a considerable potential for the invention in the future. The inner water area to the south and west of Biocoko has the potential, especially in the features of a large fan mound that is recognized on seismic data in front of the toe-push limit, which has not been tested with drilling.