Structural modelling of Agbada (Tertiary) sandstone reservoirs in “Atled Creek”, Onshore Niger Delta, Nigeria

The distribution of rocks and rock properties is an important part of an overall strategy for reservoir development, placement of new wells and prediction of future production. It also provides a detailed look into the local development of a sedimentary basin. Here we present a case-study from the “Atled Creek” concession, onshore Nigeria. A 3D structural reservoir model of the concession was prepared from available industry seismic data and well logs. Four sandstone reservoirs within the Cenozoic have been identified in the “Atled Creek” and modelled in this study to highlight variations in the reservoir properties. Four available wells were subjected to conventional well log analyses and reservoir units were mapped on the 3D seismic volume. The resulting facies and property logs were upscaled and together with the interpreted seismic horizons and faults formed the input data for facies and property modelling. This resulted in frameworks of 3D facies, petrophysical and fault models. The fault model revealed the dominance of generally W–E trending faults. A major fault trending WNW –ESE (F1) separates the reservoirs into two major blocks with the existing well located in the southern block. Fault assisted anticlinal closure is likely the prominent trapping mechanism revealed by the structural model. The reservoir model classified the reservoirs as moderate to good with total porosity of 23.8 – 34.7% in reservoir unit A, 6.3 – 33.1% in reservoir unit B,3.1 – 42.8% in reservoir unit C and 6.4 – 41.7% in reservoir unit D.