Effect of shaliness on water saturation : a case study of TN field Niger delta

Abstract EN

This study was carried out to estimate the effect of shaliness on water saturation from TN field of Niger Delta.

The conventional Archie and the Shaly-sand water saturation models were used in the evaluation of wells.

Two sand layers (Sand 01 and 02) were mapped with thicknesses range from 76.8ft to 119.3ft across the three wells for Sand 01 and 187.5 to 339.9ft across wells TN_1 and TN_4 for Sand 02.

The cross plot of the effective porosity (φe) versus volume of shale (Vsh) that was carried out, reveals a decrease in the effective porosity with an increase in shale volume.

This depicts a laminated shale pattern across the entire reservoir sands.

The petrophysical estimation of water saturation from the conventional method and the Shaly-sand models of Simandoux and Indonesia, show a clear disparity in water saturation.

This disparity recorded, was attributed to the degree of shaliness that is associated with the reservoirs, suggestive of over estimation of water saturation of the reservoirs by the conventional model.