TITLE:
Geochemical Evaluation for the Hydrocarbon Potential of Source Rocks in the Anza Basin
AUTHORS:
Bett Gilbert, Daniel Olago, Daniel Ichangi, Bernard Rop
KEYWORDS:
Geochemical Evaluation, Kerogen, Maturity, Petroleum Potential, Predictive Model
JOURNAL NAME:
International Journal of Geosciences,
Vol.12 No.6,
June
29,
2021
ABSTRACT: Anza basin is located in the extensional arm of the
central African rift system in the North-Eastern part of Kenya. Cretaceous
sedimentary rocks were sampled from the four wells namely, Chalbi-3, Sirius-1,
Ndovu-1 and Kaisut-1. Anza basin occurs on a fault block within a Paleocene-Cretaceous
rift basin. The methodological approach
used for the evaluation of source rocks included petrophysical and
geochemical methods to ascertain their potential. Well sections with a higher
shale-volume ratio were sampled for geochemical screening to determine the organic richness and thermal maturity of potential
source rocks, respectively. Source rock with organic richness ≥ 0.5% were
evaluated further for their petroleum potential using Rock-Eval pyrolysis to
determine their thermal maturity, organo-facies and in-situ generated
hydrocarbons present in sedimentary facies. The geochemical evaluation of rock
samples from the drilled wells’ sections of Chalbi-3 and Sirius-1 confirmed
both oil and gas potential. Gas Chromatography and Mass Spectrometry (GCMS)
were used to characterize the biomarker signatures and oil-oil correlation of
Sirius-1 samples. A predictive model was developed to integrate the
petrophysical and geochemical data to reveal hydrocarbons’ potential in the
Anza basin.