Advancing models of facies variability and lacustrine source rock accumulation in rifts

Implications for exploration

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Important syn-rift hydrocarbon discoveries in the Tertiary East African Rift and in the South Atlantic subsalt basins have in recent years promoted renewed interest in the variability of source and reservoir rock facies in continental rifts. This talk considers several important new observations and developments in our understanding of the sedimentary evolution of lacustrine rift basins. Offshore subsalt basins in the South Atlantic demonstrate the importance of lacustrine carbonates, and especially microbialites, as reservoir facies in extensional systems. The role of rift-related magmatism is significant in these basins, both as drivers of hydrothermal systems around and within rift lakes, and as a source of solutes that facilitate carbonate accumulations. In the Tertiary East African Rift, substantial new hydrocarbon resources have been identified, including onshore siliciclastic reservoirs in remarkably young and shallow parts of the sedimentary section in the Albertine Graben. Rollover anticlines and fault-related folds serve as important structures for several new fields in the East African Rift, but larger structures affiliated with accommodation zones, in many instances located far offshore in the modern lakes, remain untested. Lacustrine source rocks that accumulated in stratified lake basins are the source of the oil and gas in these systems, however there is still much to be learned about their spatial and temporal variability. There is observed considerable variation in the character of organic matter on the floors of modern African lake basins, even adjacent ones. A number of factors likely govern the amount of total organic carbon preserved within the basins. These include 1) primary productivity; 2) degree of siliciclastic dilution, which is controlled in part by offshore slopes and the extent of onshore catchments, and 3) physical limnology, controlled by climate and basin-scale physiography, and the fetch-depth ratio of the lakes, which determines the likelihood of water column stratification. Scientific drilling in the African Rift lake basins is providing considerable information on the high temporal hydroclimate variability of the region, especially in the later Tertiary and Quaternary, which substantially controls basin lithofacies.

Original languageEnglish (US)
Title of host publicationSociety of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016
PublisherSociety of Petroleum Engineers
Pages1-4
Number of pages4
ISBN (Electronic)9781510844834
StatePublished - Jan 1 2018
EventSPE/AAPG Africa Energy and Technology Conference 2016 - Nairobi City, Kenya
Duration: Dec 5 2016Dec 7 2016

Other

OtherSPE/AAPG Africa Energy and Technology Conference 2016
CountryKenya
CityNairobi City
Period12/5/1612/7/16

Fingerprint

Lakes
Rocks
Catchments
Carbonates
Limnology
Hydrocarbons
Organic carbon
Biological materials
Dilution
Drilling
Productivity
Gases
Water

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Fuel Technology

Cite this

Scholz, C. A. (2018). Advancing models of facies variability and lacustrine source rock accumulation in rifts: Implications for exploration. In Society of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016 (pp. 1-4). Society of Petroleum Engineers.

Advancing models of facies variability and lacustrine source rock accumulation in rifts : Implications for exploration. / Scholz, Christopher A.

Society of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016. Society of Petroleum Engineers, 2018. p. 1-4.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Scholz, CA 2018, Advancing models of facies variability and lacustrine source rock accumulation in rifts: Implications for exploration. in Society of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016. Society of Petroleum Engineers, pp. 1-4, SPE/AAPG Africa Energy and Technology Conference 2016, Nairobi City, Kenya, 12/5/16.
Scholz CA. Advancing models of facies variability and lacustrine source rock accumulation in rifts: Implications for exploration. In Society of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016. Society of Petroleum Engineers. 2018. p. 1-4
Scholz, Christopher A. / Advancing models of facies variability and lacustrine source rock accumulation in rifts : Implications for exploration. Society of Petroleum Engineers - SPE/AAPG Africa Energy and Technology Conference 2016. Society of Petroleum Engineers, 2018. pp. 1-4
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