The main objective of this study is to determine and confirm the economic viability of the Gazelle field as reported in series technical evaluation reports received from previous workers, with primary focus of developing this field as the first phase of a greater block wide strategy. A fully independent volumetric analysis was undertaken in order to ascertain the GIIP within the Gazelle structure. This involved replicating an established previous workers inputs and also re- running Monte Carlo probabilistic cases using @Risk Software. Some of uncertainties were unravelled from their inputs. The uncertainties identified from the volumetric analysis ranges from depth conversion, depth to contact, reservoir thickness, and reservoir extent (sand distributions). These uncertainties have great impact on the GRV which in turn have great impact on the over-estimated GIIP presented by the previous worker. All the geological uncertainties were quality checked (QC) in order to get correct inputs guided by oil and gas global standard. These uncertainties were unravelled by re-construction of correlation panel across the wells.
Geologically, the Gazelle Field comprises a combination stratigraphic/structural trap encompassing Cenomanian-Turonian and Senonian slope channel reservoir sequences deposited within shelf and slope setting. The field is characterised by lateral facies variability as observed from the well correlation panel; which is one of the major geological uncertainty encountered in this field.