3D structural modelling and spectral decomposition analysis of Jay Field offshore Niger Delta, Nigeria

Abstract

AbstractIn the Niger Delta, the Jay Field offshore structural model and seismic attribute analysis were carried out to enhance prospect evaluation and mitigate risk in field development operations, especially in regions with few wells and poor seismic data. Integration of a 3D seismic cube and one well with composite logs was used to carry out this analysis. Horizon and fault mapping was enhanced with Seismic attribute analysis, and an optimum frequency for spectral decomposition was identified using spectral analysis. The 3D structural framework revealed collapsed crest structures and rollover anticlines which act as hydrocarbon traping systems on the field. Detailed spectral analysis was carried out before using the spectral decomposition attribute to identify the most suitable (spectral) frequency at which the possible reservoir zones become more pronounced. The spectral frequency of 25Hz has been analysed to give high amplitude in the hydrocarbon accumulated region (indicated around the well position). This was used to evaluate prospective regions. The spectral decomposition attribute analysis predicts regions of possible quality reservoirs. This paper reveals that seismic attributes such as spectral decomposition, energy, and similarity can improve reflection patterns in poor to good quality seismic data. In this paper, the energy and spectral decomposition are veritable attributes that have improved reflection patterns and had allowed to identify anomalous amplitude associated with hydrocarbon accumulation in this paper.