The Bornu Basin, which represents a part of the Chad Basin in Nigeria, makes one-tenth of the total area of the Chad Basin that extends to the Republic of Niger, Chad and Cameroun. This basin is a sediment-filled broad depression straddling northeastern Nigeria and adjoining parts of the Republic of Chad. The cumulative thickness of the sedimentary rocks exceeds 3,600 metres. The Nigerian share of the Chad Basin is supposed to be a potential hydrocarbon-producing basin. This is because commercial petroleum accumulations totalling over 120 billion barrels have been discovered in some parts of the basin outside Nigeria (largely in the Republic of Chad) in structurally related contiguous basins. The Gongila Formation (in the Chad Basin) is a transitional sequence between the underlying continental Bima sandstone and the overlying marine Fika shale. Determining whether the shale beds present in the Gongila Formation are matured enough to generate hydrocarbons, nine wells were used and the petrophysical parameters such as total organic carbon (TOC) and total organic matter (TOM) were calculated for each of the wells. The heat flow history of the basin was calculated by establishing the relationship between the modeled thermal maturity curve and the equivalent observed maturity parameter (vitrinite reflectance). Thereafter this calculated heat flow is used to predict thermal maturity of source rocks and the timing of hydrocarbon generation. The result obtained reveals that TOC and TOM of shale sequences in each well range from 3.58 to 27.48 wt% and from 1.15 to 8.79 wt%, respectively. Thus, TOC of the Gongila Formation exceeds the kerogen threshold of 0.5 wt% for the generation of hydrocarbons while TOM exceeds the kerogen threshold of 1 wt%. The heat flow was computed from the heat generation and was estimated to range between 33 and 75 mW/m 2. The modeled vitrinite reflectance ranges between 0.56 and 0.76%Ro. It is concluded that the Gongila shale is a potential petroleum source rock. The temperature history is the factor controlling the maturation of organic compounds into fossil fuels. The Gongila Formation's thermal maturity,

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A computerized advanced statistical analysis which involves the characterization of reservoir elements involving mapping of lithofacies and pore fluids through crossplots of basic seismic variables in both bi-variate and tri-variate domains and functional transformations including rotation of axes have been used as discriminant tools over “AIB-EX” Oil Field, Niger Delta. The methodology encompasses reconstruction of geologic lithofacies information from geophysical logs. Reservoir characterization, rock physics analysis and log inversion were carried out using IHS Kingdom Advanced and Origin software. Three reservoir zones namely A, B, and C were analyzed. The obtained results characterized the reservoir elements as: shale, sandy-shale, shaly-sand and sand (with respective GR counts and P-wave velocity of 105–125 API and 2400–3600 m/s, 75–105 API and 2100–5000 m/s, 45–75 API and 2200–4750 m/s, and 10–45 API and 2000–4600 m/s) which represents seismic scale sedimentary units called lithofacies. Also, the results of both the bi-variate crossplots (GR and P-wave velocity) and tri-variate crossplots (GR, P-wave velocity, and resistivity) have not only differentiated the different lithology but have discriminated the saturating fluid (water or hydrocarbon). The pore fluids were further characterized as either brine or oil based on powerful discriminant tools such as plots of acoustic impedance versus porosity and elastic impedance versus porosity. Conclusively, the result of the research confirmed that hydrocarbon reservoirs can be discriminated with varying degree of effectiveness in various domains using the adopted approach. The obtained result, which can also be used to calibrate seismic inversion, yielded a reliable seismic lithofacies map in the presence of high resolution 3-D seismic data.

This study was conducted to investigate the basement fault propagation into the overlying sedimentary cover in parts of the Nigerian sector of Chad Basin. The Total Magnetic Intensity (TMI) map was compiled from the digital aeromagnetic data and was reduced to the equator to produce the Reduced-to-Equator (RTE) map. Residual Magnetic Intensity (RMI) map of the study area was obtained after the removal of regional trend from the RTE data. Regionalresidual separation of the RMI map was carried out using upward continuation filtering technique adopting the depths obtained from spectral analysis to produce magnetic anomaly maps associated with the basement and intra-sedimentary magnetic sources. The maxima of the Horizontal Gradient Magnitude (HGM) of the basement and intra-sedimentary magnetic anomaly maps were computed and used to delineate faults that produced the structural maps of the basement and the intra-sedimentary column, respectively. Upward continuation of the RMI map at various altitudes and the maxima of their HGM were used to highlight faults from shallow to deep depths, as well as their strikes and dips. Both major and minor faults dominated the study area. The faults strike in the directions NE-SW (Pan-African trend), ENE-WSW, NW-SE, and E-W. Two profiles were drawn on the basement and intrasedimentary maps, respectively, to model the subsurface structures. The results of this study revealed that the sedimentary section was affected by the tectonics of the underlying basement, with faults propagating from the basement upwards into the sedimentary cover. These faults constitute potential structural traps for oil accumulation or conduit for oil migration.

Recent seismic events recorded in South-western Nigeria indicate that the country may not be aseismic as had hitherto thought. Geologic and geodetic evidences suggest the existence of large fracture zones (Romanche and Charcot) beneath the area. Considering the existence of these fracture zones, and the paucity of seismicity information, the development (oil exploration and production) taking place in offshore Nigeria in the last two decades and the ambitious planning for large future projects urgently call for the implementation of a comprehensive earthquake ground motion modelling which is a useful tool in site-dependent seismic hazard assessment in low to moderate seismicity region. In this study, ground-attenuation modelling based on stochastic approach was applied to predict the expected peak ground velocity and acceleration and spectral amplifications in two geologic settings. The seismic ground motion has been modelled using the September 11, 2009 earthquake of magnitude 4.8 (Mw) as case study. Synthetic seismic waveforms from which parameters for engineering building design could be obtain have been derived. From the seismograms computed, the seismic hazard for south-western Nigeria, expressed in terms of peak ground acceleration and peak ground velocity have been estimated. The peak ground acceleration estimated for the study area ranges from 0.16 to 0.69 g, and the peak ground velocity from 18.0 to 58.3 m/sec. The high peak values of accelerations and amplifications delineated are possibly due to the presence of the low velocity layers. In general, a good correlation between the synthetic and field data was observed. These results attest to the efficacy of the modelling exercise, and assessment of the seismic risk that the region would likely be subjected to. Also, the earthquake engineering design parameters derived may be used to derive new civil engineering building codes for the affected area