Petrophysical Evaluation of Reservoirs for Hydrocarbon Reserve Estimation in Eastern Central Swamp Depobelt, Niger Delta

Abstract

Petrophysical properties were evaluated in five wells in eastern Central Swamp Depobelt, Niger Delta using well logs. Analyses by Kingdom Suite software reveal that reservoirs’ thicknesses ranged between 24.5ft in SNG in Afam 16 to 200.5ft in SNB in Obeakpu 005. Volume of shale varies within and across all the wells with values <30% of the total thicknesses. Relative permeability to water (Krw) ranges from 0.00 to >1.00 across the wells. Reservoirs SNE and SNF in Afam 16 have average Krw of 0.00 implying 100% water-free hydrocarbon production. SNC reservoir in Afam 15 and Afam 16 has average Krw >1 implying 100% water production. The relative permeability to oil (Kro) is very high in reservoirs with high hydrocarbon saturation. SNH in Korokoro 006 has average hydrocarbon saturation of 85.70% and Kro of 0.89. SNB in Obeakpu 005 has average absolute permeability of 62,086.9mD. Reservoirs SNB, SNC and SND contain no producible hydrocarbon in Afam 15 but contain producible hydrocarbon in Afam 16, Korokoro 003 and Obeakpu 005 wells. Reservoirs SNE, SNF, SNG and SNH in Afam 15, Afam 16, Korokoro 003 and Korokoro 006 contain producible hydrocarbon with the exception of SNF in Korokoro 003. Afam 15 and Afam 16 are mainly gas-producing with estimated gas-in-place ranging from 72,630.27cu.ft/acre in SNB in Afam 15 to 1,534,667.86cu.ft/acre in SNH in Afam 16 while Korokoro 003, Korokoro 006 and Obeakpu 005 are mainly oil-producing with estimated oil-in-place ranging from 47,590.26bbl/acre in SNB in Korokoro 003 and 387,754.83bbl/acre in SNB in Obeakpu 005.