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Previous studies revealed that soil properties play a significant role in aquifer contamination. Consequently, it is necessary to understand the nature and properties of soil in carrying out groundwater evaluation. This study evaluates the subsurface geology and groundwater flow direction in Okpagha, Iguomo, Ikhueniro and Okhuahe suburbs in Benin City, Nigeria. Six boreholes were drilled by means of manual (rotary) method in different parts of the study area and each borehole was logged in order to understand the lithology, depth to water table, static water level as well as flow direction. The results obtained show that aquifer within the study areas were confined, semi confined to unconfined and was dominated by sands with minor clay and lignite interbed. It was observed that aquifer becomes shallower towards eastern portion of the study areas with increase in sand and decrease in clay materials. It was also observed that groundwater flow map revealed a flow direction of NorthWest to SouthEast from North West to South East. The decrease in the depth of aquifer and increase in sand material could be explained by the closeness to sea level. This phenomenon can enhance the infiltration of contaminants into aquifer thereby contaminating the groundwater bodies. It is therefore necessary to constantly monitor the groundwater quality in this suburbs in order to be aware of the quality of water resources being consumed because poor water quality can impact public health negatively. Furthermore, the authors advise that boreholes should be drilled in the direction of groundwater flow for maximum yield

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Integrated wireline logs and lithostratigraphic techniques were employed to determine the lithological and petrophysical properties of wells A and B in E- field, onshore Niger Delta. The Reservoirs in both wells were analyzed using a minimum thickness or depth of penetration of 5.0m. For the two wells, Gas Water Contact (GWC), Gas Oil Contact (GOC), and Oil Water Contact (OWC) were found to be present at varying formation depths. GWC, GOC, and OWC at depth of 2967.50m, 3348m and 2286m respectively for well A and a GOC at depth 1715m for well B. The correlation of both wells reveals a gas reservoir, water reservoir, and a non-resistive, but highlyconductive zone at 2450m, 2500m, and 2150m depth respectively. The formation porosity (∅𝑫), total porosity (∅𝑻), effective porosity (∅𝑬) and resistivity values of well A ranges from (27.27 - 39.59) %, (1.3x10 –1 - 37.82) %, ( 1.638x10– 4 – 81. 38)%, (2.05 - 150)Ωm respectively. Conversely, well B measured (27.27 - 36.50) %, (2.25x10–2 - 93.0) %, (9.75x10– 4 - 32.79) % and (2 – 200) Ωm respectively. Hydrocarbon saturation (SHC) and Bulk volume of Hydrocarbon (BVH) for well A ranges from (73.27-95.10)% and (24.24 - 34. 58)% while that of well B ranges from (77.10 - 97. 90)% and (23.36 - 35.53)% for SHC and BVH respectively. The average ∅𝑻 and ∅𝑬 of 56.2% and 42.6% reveal excellent porosities in well A and reservoirs 2,3,4a and 11 in well B with average ∅𝑻and ∅𝑬 of 37.82% and 30.6% also show an excellent porosities. The result from the Petrophysical indices indicates pay zones at reservoirs 10a, 10b and 11 in well A andreservoir 11 in well B which are predominantly gas reserves. Keywords: Reservoirs, Onshore, Oil and Gas, Petrophysical properties, Niger Delta and Lithology

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