3d Seismic Structural Interpretation of a Part of Aloo-Field, Southwestern Niger Delta, Nigeria

Abstract

Complexity of faulted subsurface configuration causing erroneous deductions in absence of well articulated interpretation approach led to a well refined 3D seismic data of part of ALOO-Field located in offshore southwestern Niger Delta. This study was aimed towards determining its subsurface structural features and retentive capacity of the reservoir for hydrocarbon. The methods employed include analysis of 3D seismic data using Petrel software; horizons and fault deductions from the seismic sectionwere used to generate structural maps which revealed different structural styles present in the studied area. Three distinct horizons were mapped. Depth structural maps generated for all surfaces of interest show subsurface features such as the geometry of the identified horizons, W-E trending growth fault, fault echelonsof which most of them dip to the east and fault assisted closures at the north-western-central part of the studied section. The dipping pattern of the identified faults coincides with that of the growth fault which enhances trapping mechanism for the hydrocarbon. Two principal structural trapping mechanisms present are growth fault and rollover anticline which are synonymous with Niger Delta. The study has demonstrated the importance of seismic structural interpretation in understanding the structural styles present and their retentive ability for hydrocarbon. Keywords-Fault echelons,Growth faults, Rollover anticline, Seismic Sections, and Structural styles.