Interpretation of high resolution aeromagnetic data to determine sedimentary thickness over part of Bida Basin, North Central Nigeria

Abstract

This study focuses on the quantitative interpretation of aeromagnetic data to estimate the thickness of sediments over part of Bida Basin so as to identify possible areas of hydrocarbon potential. The study area covers an area of 24,200 km2 located between latitude 8° 30ꞌN and 9° 30ꞌN and longitudes 5° 00ꞌE and 7° 00ꞌE. Aeromagnetic data in grid format containing eight sheets were analysed and interpreted. Polynomial fitting was used in regional/residual separation and this result to the residual field data that corresponds to the target source for further processing. Three depth estimating methods were employed in this study; Euler deconvolution, source parameter imaging and spectral depth analysis. Euler depth determination method reveals a maximum depth of 3.56 km around Mokwa and Batati areas. Shallow sources also exist around Pategi, Paiko, Izom and Lapai areas with an average depth ranging from 107.74 m to about 514.82 m.  Source parameter imaging shows a deeper sedimentary thickness of 4.2 km in the same area with Euler deconvolution. Spectral depth analysis also showed a maximum sedimentary thickness of 3.50 km. It was found in the study that the maximum depths obtained might probably be sufficient enough for hydrocarbon maturation and gas accumulation. Further research using seismic reflection might be carried out in the areas where maximum depth was obtained. Key words: Aeromagnetic data, polynomial fitting, spectral analysis, euler deconvolution source parameter imaging.