Publications

This study presents the effect of permeability anisotropy; maximum horizontal permeability (kx), horizontal permeability of 90o (ky), and vertical permeability (kz), in applying rock typing while only maximum horizontal permeability is commonly used for reservoir characterization. Samples from Berea sandstone (measured in laboratory), Nugget sandstone (published data), and Shannon sandstone (published data) are used in this study which are available for the value of kx, ky, and kz. Common rock typing method, Winland, HFU, GHE, and PGS were applied to classify the samples by using all tensor permeability with each pair of porosity at the same depth. Yet, with those methods, each permeability tensors shows a different classification even though they are from the same depth. Therefore, this study develops a general of rock grouping methods in which by using kx, ky, and kz in rock typing will define an object consistently. Furthermore, this paper provides a new approach in laboratory measurement to avoid anisotropic permeability miss prediction and an analytical solution for estimating 90o horizontal permeability (ky). Calculation result with the proposed method yield satisfying result, while comparing to measurement data. So that, it can be applied to predict 90o horizontal permeability (ky) in the reservoir grid model while it is very rare to be measured and commonly ignored, meanwhile the 90o horizontal permeability is not always equal with maximum horizontal permeability. This is essential when the reservoir topography is an inclined plane in case of vertical permeability and horizontal permeability of 90o also play a role in delivering fluid.