A pre-salt play?

Deep Plays in Angola

Angola’s oil industry continues to benefit from new oil discoveries and ever increasing oil production, according to a paper presented at the Deepwater Offshore West Africa Conference (DOWAC) by AAPG member and Public Service Award winner Tako Koning. This conference was held November 14 - 18 in Abuja, Nigeria.

Cubal River gorge, south of Sumbe, Angola exposing Upper Cretaceous carbonates of the Kwanza Basin. These carbonates correlate to the Pinda Formation limestones and dolomites which have produced over 1.5 billion barrels of oil in shoal deposits in the shallow water areas of the Lower Congo Basin. Photo courtesy of Tako Koning
Cubal River gorge, south of Sumbe, Angola exposing Upper Cretaceous carbonates of the Kwanza Basin. These carbonates correlate to the Pinda Formation limestones and dolomites which have produced over 1.5 billion barrels of oil in shoal deposits in the shallow water areas of the Lower Congo Basin. Photo courtesy of Tako Koning

Koning’s paper, “An Overview of the Geology and Geophysics of Angola’s Oil and Gas Fields and Related Industry Activity,” showed that in comparison to Nigeria, where one-third of its oil production is from the deepwater, two-thirds of Angola’s production is from the deepwater.

Accordingly, the deepwater oil play is vital to the long-term continuation of Angola’s oil industry.

Koning stated that within the past decade Angola has almost doubled its oil production to two million barrels per day. He explained that the Angola success story is due to:

  • World class petroleum working system, including excellent source and reservoir rocks.
  • Superb seismic imaging, which has led to an approximate 80 percent drilling success rate in the Lower Congo Basin.
  • Contractual stability – when a contract is signed between Sonangol, the state oil company and an oil company, it remains “fait accompli” during the life of the contract.
  • Political stability – despite Angola’s long civil war from independence in 1975 until 2002, Angola has experienced remarkable political stability with the same political party (MPLA) in power since independence and with President Eduardo dos Santos being head of state since 1979.
Miradoura da Lua, near Luanda, Angola, where shallow marine Tertiary (Miocene) aged sediments of the Kwanza Basin outcrop. These sediments are stratigraphically equivalent to the Miocene and Oligocene turbidite channels that currently are producing about 1.5 million barrels of oil per day in the deepwater Lower Congo Basin. Photo courtesy of Tako Koning
Miradoura da Lua, near Luanda, Angola, where shallow marine Tertiary (Miocene) aged sediments of the Kwanza Basin outcrop. These sediments are stratigraphically equivalent to the Miocene and Oligocene turbidite channels that currently are producing about 1.5 million barrels of oil per day in the deepwater Lower Congo Basin. Photo courtesy of Tako Koning

Koning also mentioned the minimally explored pre-salt oil play in Angola has captured the interest of the global oil industry.

In Brazil’s Santos Basin, giant size oil and gas discoveries continue to be made in the pre-salt sedimentary section. These discoveries will likely lead to Brazil’s current oil production of two million barrels of oil per day doubling to at least four million barrels of oil per day. During Cretaceous time, Angola was juxtaposed against Brazil (“joined at-the-hip”), thus it is possible that Angola’s oil production could likewise double if the play proves to be geologically and economically successful, he said.

The pre-salt play is not only relevant to Angola, but also is highly relevant to the deepwaters of Congo Brazaville and Gabon.

Koning also showed that West Africa is an important supplier of crude oil to the United States, which remains as the world’s largest oil importing country.

West Africa provides the United States with 15 percent of its import requirements.

Crude oil from West Africa is high quality low sulphur crude, he said, and is welcomed by refineries anywhere in the United States.

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Why it Matters

By TAKO KONING

The third Regional Deepwater Offshore West Africa Conference and Exhibition, commonly known as DOWAC, was held in Abuja, the capital city of Nigeria from Nov. 14-18, with the theme “West Africa Deepwater: Success, Challenges and Future Prospects.”

AAPG was represented by Vice President-Regions Alfredo Guzmán; Africa Region President Nosa Omorodion; and, representing AAPG’s Tulsa headquarters, Regions and Sections manager Carol McGowen.

West Africa continues to be an oil and gas “hotspot” within the world’s “golden triangle” for deepwater oil exploration and development. This triangle consists of the deepwater Gulf of Mexico, Brazil and West Africa.

The two mainstay areas of deepwater activity in West Africa continue to be Angola’s Lower Congo Basin and Nigeria’s Niger Delta Basin. The deepwater area continues to expand, however – northward and westward to Ghana, where the Jubilee oil field with reserves of about 1.5 billion barrels was to begin production last month.

Indeed, from Ghana the deepwater play has now been extended some 800 kilometers west to Sierra Leone, where in 2009 Anadarko drilled the Venus B-1 deepwater oil discovery, and subsequently last year drilled Mercury-1, another oil discovery in 5,250 feet of water.

Current oil production in West Africa (data from USA EIA/Energy Information Administration) is:

  • Nigeria – 2.4 million (barrels of oil per day).
  • Angola – 2 million.
  • Congo (Brazaville) – 440,000.
  • Equatorial Guinea – 320,000.
  • Gabon – 245,000.
  • Chad – 145,000.
  • Cameroon – 75,000.
  • Ivory Coast – 30,000.
  • Congo (DRC) – 25,000.
  • Mauritania – 10,000.
  • Ghana – 5,000.

That all adds up to 5.695 million barrels of oil per day from West Africa. West Africa also is an important producer of liquefied natural gas.

West Africa also is an important producer of liquefied natural gas.

  • Nigeria –15 million tons per year (current production).
  • Equatorial Guinea – 3.5 million tons per year.
  • Angola – 5.2 million tons per year (commencing 2012).

Keynote speaker Mark Ward, lead country manager for ExxonMobil Nigeria, reported there has been a decline in deepwater activity since 2005 – but improvements in fiscal terms could lead to a turnaround in drilling activity and commensurate oil production.

DOWACs have been held every three years, and informal discussions in Abuja suggested that perhaps the next DOWAC should be held in 2014 with Accra, Ghana being the appropriate location since by that time Ghana will have blossomed into being an important West African oil and gas producer.

Meet Tako Koning

Tako Koning
Tako Koning

Tako Koning, an AAPG Public Service Award winner, is a 33-year member of AAPG and is a long time resident of Angola where he currently works as a consultant for Gaffney, Cline & Associates. He also continues as a part-time (volunteer) Residential Representative for the Norwegian NGO, Yme Foundation, which drills wells for drinking water in rural areas of Cabinda province, Angola. He has attended all three DOWAC’s (2004, 2007, 2010) and views attendance at the DOWAC’s as a “must” for anyone involved in West Africa exploration and production.

Emphasis: World Development