Using Physics of Seismic Wave Propagation in 3-D Orthogonal Geometry for Hydrocarbon Exploration in Benue Trough, Nigeria

Abstract

The need for Nigeria's improved revenue base necessited exploration for hydrocarbons in the frontier basins in addition to such exploration going on in the Niger Delta. This study is aimed at showing the role of physics in the exploration for hydrocarbons using seismic waves in 3-dimensional orthogonal geometry acquisition design to locate hydrocarbon traps in the Benue Trough. The method begins with the acquisition geometry design with a swath consisting of six receiver lines orthogonal to the source lines and having 200 m line spacing each, 48 shots per salvo, 12.5 m by 25.0 m bin size, 25.0 m receiver stations intervals, 50.0 m source point intervals, a maximum offset of 5261 m, a maximum multiplicity of 150, and 2400 (400*6) active channels. The recording materials and equipment were deployed as designed above, and the Sercel SN428XL recording instrument was used for the seismic data acquisition, while a 2 ms sample rate and 8-second record length were retained throughout the study. The result of the preliminary field processing showed a subsurface image with stratigraphic traps for hydrocarbon (oil and gas) between 400 ms and 2000 ms travel time on the unmigrated brute stack section.