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While the world is transitioning into a greener and less-carbon-rich energy source, the fact remains that there is a growing need for exploration and production of hydrocarbons in previously untapped resources. These frontier reservoirs, while extremely hot, are prolific and make the footprint of the exploration activity much smaller than shallower drilling, which would require many more wells to deliver the same amount of hydrocarbon. HP/HT wells can be found offshore in the North Sea and Gulf of Mexico, or on land--as seen recently in the Gongola Basin. Fluid identification, which is a critical process in fluid sampling, continues to be a challenge in temperatures above 350 F. At temperatures up to 450 F, fluid identification is currently achieved by bubblepoint and compressibility measurements, which cannot quantitatively measure contamination levels of the subject sample fluid. A possible solution to this problem would involve using pyroelectric detectors in the process of estimating a property of a downhole fluid.
The Benue Trough has been generally described as an elongate rift filled with Cretaceous sediments that are up to 6000 meters thick and has been divided into the Lower, Middle and Upper arms. The Benue Trough is itself a product of the West and Central African Rift System. Several models have been put forward for the evolution of the Trough but all of them still remain controversial due to insufficient data on its tectonic framework, thermal history, and relationship between tectonics and sedimentation. The purpose of this study is to interpret available new aeromagnetic data to study the tectonic framework of part of the trough (Upper-Benue trough) with a view to understanding the evolution of the trough. NigeriaSat-X and SPOT 5 imageries covering the basin were processed and interpreted and lineaments mapped out from them with the aid of the digital elevation model (DEM) of the basin. Several enhancement transforms such as first vertical derivative (FVD), Tilt derivative (TDR) and Total horizontal derivative (THDR) were applied to the total magnetic intensity (TMI) grid of the basin after which the basement faults were mapped out. The depths to the source hence sedimentary thickness were also derived from the magnetic field using methods like Spectral Analysis and Source Parameter Imaging (SPI) or Local wavenumber. The lineaments from the SPOT 5 data show a predominant NNE-SSW, NE-SW followed by the NNW-SSE with a few N-S and E-W trends and the basement configuration show a predominantly NE-SW trend which is the predominant trend in the Benue Trough while a few strike in the N-S,NW-SE, and WNW-ESE direction. This suggests that the basin was subjected to several stress regimes. Differential uplift of the basement fault blocks may also have given rise to drape folds observed in the overlying sediments. The Benue Trough maybe an old rift that has gone through several processes such as block faulting, volcanism, emplacement of basic igneous material within the basin and that all volcanic activity ceased before the Tertiary. The sediments of the Gongola and Yola arm of the basin have potential for hydrocarbon generation. Presentation Date: Tuesday, October 13, 2020 Session Start Time: 1:50 PM Presentation Time: 2:15 PM Location: Poster Station 6 Presentation Type: Poster
Abstract The present investigation focused on geochemical evaluation of shale sequences in The Lower Benue Trough using geostatistical approach Thirty two representative samples of shale sequences of The Asu River Group, Nkporo Group and Mamu Formation in The Lower Benue Trough were subjected to Multi-Parameter study in an attempt to present a model of the sediment provenance, and paleoenvironment diagenetic conditions. The X-ray diffraction and Inductively Coupled Plasma Mass spectrometry (ICP-MS) techniques were employed to examine and establish qualitative and quantitative constituents of the Major oxides, Trace and Rare Earth elements. The major minerals determined include SiO2 (40.96%, 56.08% & 60.39%)2, Al2O3 (15.09%, 18.27% and 21.16%), TiO2 (0.75%, 1.73% and 1.63%) and Fe2O3 (9.66%, 2.78% & 2.85%), for Asu River Group, Nkporo Group and Mamu Formation respectively. The studies suggest high influx of sediments into both The Abakaliki Anticlinorium and the Anambra Basin. When tested with multivariate statistical techniques such as Factor, Principal Component, Correspondence and Cluster analyses, the hidden affinities within the sediments were revealed in terms of similarities and dissimilarities. Enrichment and depletion of biogenic indicators CaO (EF=1.87 − 0.01) and P2O5 (EF=1.58 − 0.33) in the studied Asu River Group and Anambra basin sediments indicate deep marine to marginal marine paleoevironment of deposition respectively. Chemical examination of the maturity indexes indicate that the Anambra basin sediments were more matured, indicating that most of the Anambra Basin sediments were reworked from the Abakaliki Anticlinorium.
Raji, Jamiudeen Kayode (Department of Petroleum Engineering and Geosciences, Petroleum Training Institute, Effurun, Delta State) | Adebowale, Ademola Olabisi (Department of Petroleum Engineering and Geosciences, Petroleum Training Institute, Effurun, Delta State)
Abstract Forty six (46) shale samples were collected from borehole, quarry and outcrop in the Northern Benue Trough which consists of Gongola and Yola Basins respectively. The Gongola Basin comprises Bima Formation, the Yolde Formation, Pindiga/Gongila Formation and capped with Gombe Formation whereas the Yola Bain consists of Bima Formation, Yolde Formation, Dukul/Jessu/Numanha Formation and capped with Lamja Formation. The samples were subjected to vitrinite reflectance, Rock Eval pyrolysis and infrared spectroscopy in order to evaluate their organic richness, thermal maturity and petroleum generating potential. The total organic carbon (TOC) values of the Gongola Basin are between 0.20 and 2.46 wt. % averaging 0.70 wt. % while that of Yola Basin range from 0.11 to 12.9 wt. % averaging 1.50 wt. %. The mean random vitrinite reflectance (Rom) values in the Gongola Basin range from 0.48% in the Gombe Formation to 0.65% in the Pindiga Formation and 0.67% in the Gongila Formation. Also, the reflectance values in the Yola Basin increase with stratigraphic age ranging from 0.63 to 0.80% in the Dukul and Yolde Formations respectively. The thermal maturity of the organic matter (Tmax) values from the pyrolysis of shales in the Gongola Basin is between 420 and 440°C while that of Yola Basin range from 435 to 445°C. The plot of hydrogen index (HI) vs Tmax for classification of kerogen in the Gongila and Pindiga Formations reveals prevalence of Type III kerogen while that of Dukul and Yolde Formations shows Type II – III kerogen. The results obtained suggest that Gongola Basin source rocks are fair and thermally immature to marginally mature and have potential to generate gas in the deeply buried section whereas the Yola Basin source rock are between fair to good and thermally mature with potential to generate oil and gas in the deeper section.