Geology and Petrophysical Analysis of Oredo Oil Field in Niger Delta Basin, Southern Nigeria

As part of the IDSL expedition in 2008 to the southern Niger Delta, numerous well data were collected to evaluate the quality of reservoirs within the basin. Oredo field was explored accordingly. On the basis of regional lithostratigraphic studies from logging tools, a more highly reflective, coarse-grained sediment unit of late Miocene age is identified as the largest hydrocarbon reservoir. The Miocene reservoir is locally above present-day regional datum. Literature has suggested that oil and gas production can be expected at depth in Jurassic, Cretaceous and Tertiary source rocks, the presence of high-amplitude reflector packages within the reservoir unit is interpreted as an evidence of hydrocarbons. Six discrete reservoirs were encountered in two wells. Log signals indicated a thick seal just above the reservoir unit shown on both of Oredo-1 and Oredo-2 Well. Generally, the encountered reservoirs are of good quality. The average effective porosity from the wells ranges from 0.14 to 0.25 across the vertical successive reservoirs, implying fairly good porosity condition for commercial accumulation of hydrocarbon. The Permeability of the encountered hydrocarbon-bearing reservoirs are also generally good and range from 27 to 236 md and water saturation of between 51 to 87 in the areal acreage.