Browsing by Author "Eze, S."

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    Delineation of Laterite Deposits using Two-Dimensional Geo Electric Imaging in Agbonmwoba Village Area of Obaretin Town, Edo State, Nigeria.
    (Sabinet / African Journals, 2017) Osisanya, O.W.; Ibitoye, A.T.; Eze, S.; Ezomo, F.O.; Okeh, O.
    The study involves delineation of laterite deposits in Agbonmwoba village area of Obaretin town, Edo state using 2D resistivity tomography technique to predict the extent and the economic viability of the deposit, in order to improve wellbeing status. The Petrozenith earth resistivity meter was employed using the Wenner Schlumberger electrode configuration. Five different locations were investigated within the study area, and a total of ten (10) Wenner-Schlumberger soundings were acquired in the area with a spread length of 200m along each traverse. The field data was inverted using the Zondres 2D software. Four (4) lithologic units were delineated namely; clay deposit with resistivity range of about 1 – 100Ωm, sand deposit with resistivity range of about 200-570Ωm, laterite deposits with resistivity distribution overlapping from about 1000-3162Ωm and gravel deposit whose resistivity distribution ranging from about 8000-10,000Ωm. Laterite deposit were found along traverses 1, 2 and 8 sampled at old sapele road Ekiosa at depths of 13-15m in TR 1, 10-15m in TR2, and 5m in TR8 at horizontal spread of 40-90m, 10-20m, and 20-170m respectively. Laterite deposit were found along traverses 3 and 4 sampled at presco road Obaretin at depths of 10-15m in TR3, and 10-15m in TR4 at horizontal spread of 140-160m, and 160-180m respectively and also laterite deposit were found along traverses 5, 6 and 7 sampled at Agbonmwoba primary school at depths of 5-15m in TR5, 5m in TR6, and 15-25m in TR7 at horizontal spread of 40-50m, 50-70m, and 110-120m respectively. Traverse 9 showed no evidence of laterite deposit from its resistivity pseudo-section. The result shows that laterite deposits along traverses 1, 2, 3, 4, 5, 7, and 10 are located almost at the same depth within the subsurface which implies that the subsurface geology distribution along these traverses are homogenous, and the laterite deposits along these profiles is commercially viable for exploitation, while the laterite deposits delineated along traverses 6, and 8 in the study area are not homogeneously distributed with those delineated along other traverse at the depth imaged and as such is not commercially viable. The results were further compared with borehole lithologic section drilled along TR5 in the area and both sections agreed. Thus 2D resistivity imaging gives a better lateral view of the subsurface layers than geo-electric section computed from 1D models because of its ability to give a continuous record of subsurface formations at greater depth.
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    Unloading Mechanism: an Indication of Overpressure in Niger Delta („X‟-Field) using Cross Plots of Rock Properties
    (Seventh Sense Research Group, 2018) Eze, S.; Ideozu, R.U.; Ibitoye, A.T.; Osisanya, O.W.; Tiekuro, E.
    This study has investigated the unloading mechanism causes of overpressure and delineated the overpressure zones in X- field Niger Delta. The Niger Delta basin has many overpressure zones with different origins and depositional environments. This research used well log data from four (4) wells in X - Field Niger Delta. The logs include Gamma ray log, deep induction log, Density log, and sonic log. Densities and p-wave velocities derived from sonic log were cross plotted using the E log modelling tool embedded within Hampson-Russel software application. The crossplots were subjected to over pressure analysis. The results obtained revealed Unloading mechanism from 5341ft (1627.9m) to 6448ft (1965.4m) and overpressure zones from 4234ft (1290.5m) to 4788ft (1459.4m) about 168.86m thick within well 01, Unloading mechanism from 2289.5m to 2298.3m and overpressure zones from 2280.7m to 2285.1m within well 02, also Unloading mechanism from 3246m to 3335m and overpressure zones observed from 3157m to 3201m within well 03, and finally Unloading mechanism observed from 5970ft (1819.7m) to 6677ft (2035.1m) and overpressure zones observed from 4554ft (1388.1m) to 5262ft (1603.8m) (about 215.79m thick) within well 04. The results obtained in the over-pressured zones occurred in similar depths in parts of the Niger Delta Basin. The areas identified as overpressure zones should be critically examined prior to drilling to avoid blowout. This study has delineated overpressure zones and unloading intervals in the study area using well logs and crossplots.