Detecting Channel Sands using Spectral Decomposition on 3-D Seismic Data: A case study

The Lower Cretaceous Zubair Formation in Kuwait ranges in thickness from around 1150ft in to 1450 ft . It consists of sandstone and shale alternation. Thin sands were encountered at the base of the formation in many wells in a northern field of Kuwait. The sands are isolated and discontinuous. Later a thick reservoir fluvial sand (of about 54 ft) was encountered in a single deep exploratory well in the field. This sand could not be mapped on conventional way on amplitude seismic data volume due it's complex geometry, low signal to noise ratio and complex fault system at reservoir level. However this sand was delineated by use of state of art interpretation tools like spectral decomposition and RGB image blending. Subsequent drilling of the play confirmed the channel geometry of the reservoir. The study, for the first time, upgraded the prospectivity of the Zubair Formation in the field and highlighted potential sweet spots for further exploration and development.