Derivation of refraction statics solution for 3D seismic data in an onshore prospect Niger Delta field

Abstract

The near-surface imaging and characterization of an onshore prospect field in the Niger Delta was successfully carried out in a previous study (Adizua et al. 2019) using an integrated approach of combining inversion of refracted arrivals and uphole measurements. The output of that study which revealed the layer characteristics of the near-surface (0–500 m) over the prospect field is now being used as a starting model to derive a complete refraction statics solution to be adapted for processing the 3D seismic dataset from the prospect field. The complete statics solution derived included the field or datum statics, refraction statics, and the 1st and 2nd residual statics which addressed the unresolved and remnant spatial long and short wavelength statics effect on the traces across the investigated field. The comprehensive solution was then incorporated into a PROMAXTM routine and applied to the seismic datasets using appropriate flow commands to perform the statics correction procedure. The outcome of the derived and implemented statics correction was demonstrated on shot gathers from the field in FFID configuration. Results from the several shot gathers analyzed after the application of the statics correction across the field showed that traces were adjusted back to their appropriate positions. The reflectors became better aligned and assumed a near-hyperbolic pattern which is a positive indication that the derived and applied refraction statics solution was the most appropriate for the dataset.