Enhanced hydrocarbon recovery using the application of seismic attributes in fault detection and direct hydrocarbon indicator in Tomboy Field, western-Offshore Niger Delta Basin
AbstractSeismic stratigraphic and structural interpretation is often hampered by seismic resolution and, sometimes, human's inability to identify a subtle feature on the seismic. These factors have frequently led to the poor seismic interpretation of geologic features. Thus, an integral approach to studying the structural patterns and hydrocarbon bearing zones using seismic attributes were carried out on the Tomboy field using 3D seismic data covering approximately 56 km 2 of the western belt of the Niger Delta. The seismic volume underwent post-stack processing, which enhanced seismic discontinuities. A deep steering volume was first created, and several dip filters were applied to enhance faults in the study area. After that, curvature and similarity attributes were calculated on the dip-steered and fault-enhanced volume. These calculations show detailed geometry of the faults and zones of subtle lineaments. Six faults (F1, F2, F3, F4, F5, and F6) were identified and mapped. These faults range from antithetic to crestal growth faults. Two major growth faults (F5 and F6) were revealed to dip in the NE-SW directions. A near-extensive crestal fault (F4) appeared beneath the major faults. Although several minor fractures were displayed in the southern and central portion of the seismic data, the SW dipping crestal fault (F4) and growth fault F6 are responsible for holding the hydrocarbon found within the identified closures. Using attributes on the seismic data increased confidence in the mapping and interpreting structural features. Furthermore, Energy attributes were used as Direct Hydrocarbon Indicator (DHI) to visualize viable areas within the study and permits a more robust interpretation. Time slices were taken at regions of flat and bright spots. Spectral decomposition attribute was run on these slices to display areas of high amplitude reflection typical of hydrocarbon-bearing regions, which are trapped mainly by regional to sub-regional growth faults. The surface attribute calculated on the generated surface shows that the field is dominantly controlled by faults serving as traps for hydrocarbon.