3D Reservoir Characterization of Field Deta, Termit Basin, Niger

Field Deta is located in the south-west area of Agadem Block. Agadem Block (27516.2 km(2)) covers main part of Termit basin. The Termit basin is believed to be rifting basin (Genik, 1992, Tectonophysics, 213(1-2): 169-185) [1] with graben structures. The total studied surface area of Field Deta covered by 3D seismic is about 945 km2. There are total of 12 wells drilled in the area of study mentioned above. The hydrocarbon is discovered from Alter Sokor formation which is divided into 6 sand groups: E0, E1, E2, E3, E4, and E5. The average thickness of sand groups ranges from 80 to 140 m. E2-E4 is the major oil zone; meanwhile, partly of the E5 sands had found some compartmentalized gas. Hence, this study aims to understand the highly faulted horst and graben structurally controlled reservoirs. Besides this study also reviews the radioactive sand thickness and low-resistivity pay interval that will affect the hydrocarbon assessment. Radioactive sand can be differentiated and studied using SGR log by plotting Th/K crossplot and density-neutron crossplot. The Shaly-sand intervals interpretation and petrophysical characterization are carried out taking into account the radioactive sand. Aware about the potential low-resistivity pay, resistivity index of deep resistivity log is compared. 3D seismic volume is interpreted with regard to different seismic attributes to enhance structural interpretation.