Application of the uphole seismic data in the determination of the weathered layer profile in east-central Niger delta Nigeria

Abstract

A total of 10 uphole data was acquired and analyzed from a seismic prospecting area of the East-Central Niger Delta, Nigeria. The thickness and velocity of the low velocity layer (LVL) was determined. Refraction statics was computed automatically from first break picks using CGG’s SDITR interactive programme. The seismic data section with and without static correction were discussed. Normal move out correction was applied to the data collected using CGG’s automated VELCOM programme. An interpretation of the data, carried out using the time-depth plots, shows that the thickness of the low velocity weathered layer is variable between 3.0m to 20.5m with an average of 6.7m. The velocity of the weathering layer ranges between 482m/s and 1147m/s with an average of 836.2m/s, while the velocity of the sub-weathering layer varies between 1601m/s and 1832m/s with an average of 1701.3. The knowledge of this weathering structure can be applied in oil and ground water exploration. Also this structure could be used by groups interested in civil engineering.

KEYWORDS: Low velocity layer, uphole, statics correction, normal move out correction, seismic refraction.