Integrated Approach to Identify Stratigraphic Prospect from Sparse 2D Seismic Attributes (AVO), Well Correlation and Geological Model – A Success Case from Genale B-2X in Blocks 3&4, Ogaden Basin, Ethiopia

Genale B-2X is a vertical wildcat exploration well drilled in Blocks 3 & 4 (Genale), Ogaden Basin onshore Ethiopia, 590m above sea level. The well is located approximately 800 km to the southwest of capital Addis Ababa, 15 km northwest of Genale-1 and 40 km southeast of El Kuran-1. It was drilled to evaluate the hydrocarbon potential in the Gumburo and Calub reservoirs. Geometrically, Ogaden Basin is divided into two sub-basins namely Western sub-basin which was relatively sagged during post Triassic period and Eastern sub-basin which was tectonically active throughout Permian to Tertiary period (as shown in the Figure 1). Prior to drilling, prospect Genale B was identified by bright seismic anomalies, extraction of seismic impedance and AVO seismic attributes from sparse 2D seismic data shot by PETRONAS Carigali Overseas Sdn Bhd (PCOSB) in 2006. The prospect is situated at the western flank of Ogaden Basin that experienced minimal structuration due to its close proximity to Negele Basement which shielded the blocks from intensely being further rifted. The well was successfully penetrated the Gumburo and Calub reservoirs respectively. Based on the petrophysical evaluation, three gas bearing reservoirs are identified in the Gumburo formation namely Upper Gumburo, Lower Gumburo and Middle Gumburo (Figure 2). High gas reading during drilling was observed in these reservoirs.