Reservoir Assessment Through Facies Analysis, Petrography and “Kotyakhov” Aproach: A Case Study of the Sandy Members of Pindiga Formation, Northern Benue Trough (Gongola Sub-Basin), NE Nigeria

Abstract

The Gongola sub-basin of the Northern Benue Trough (NE Nigeria) is a frontier hydrocarbon exploration basin that is presently under investigation. It is part of the West and Central African Rift System (WCARS), a rift system from which several petroleum exploration successes have been recorded. The Nigerian economy relies heavily on oil and gas that are currently being exploited in the Niger Delta petroleum province; it accounts for about 10% of domestic products and its revenue represents 
around 86% of total export revenue. Consequently, in order to expand the country’s resource base and to search for replenishments to the existing reserves, it is imperative to explore for hydrocarbons in the inland frontier basins, especially the Gongola Sub-basin of the Upper Benue Trough, where exploration activities have recently kicked off. This research has confirmed key controls on the morphology of the depositional environments of Sandy Members of Pindiga Formation using the influence of wave, tide, and river processes, which are controlled by shoreline movements with sediment supply and accommodation. The sandy members show good porosity values ranging from 7.0 to 34.0% (average ϕ = 15.7%), with many 
beds having very good to excellent permeability values range from 41.9 to 217.6 mD with an average of 89.3 mD, which is classified as a fair to high reservoir. The quality of these reservoir sands is strongly linked to their depositional systems, and this research can serve as a guide for future seismic exploration, especially within the Gongola sub-basin.