Successful management of carbonate reservoirs largely depends upon accurate description of their geological and petrophysical characteristics that affect storage and flow of the oil & gas. Therefore, a clear identification and description of changes in facies, porosity and permeability is needed. While the coring and core analysis are ideal for the purpose, they are too expensive to be used routinely in a field development. Electrical borehole imaging technology- that can resolve millimeter size bedding and textural features in rocks, when combined with a full suite of the open hole logs, offer powerful means of characterizing facies and the pore space. Recently the image interpretation has been further enhanced so as to partition- and quantify the pore space (Chitale et al, 2004 and 2008; Xu et al, 2005) in carbonates into micro-, primary interparticle- and secondary porosity. The new integrated interpretation method now also uses NMR and acoustic logs together with the high resolution electrical borehole image and the “Triple combo” to accomplish the porosity partitioning as also to estimate the permeability of the carbonate reservoirs.
Author : Ananda S Roy, M S Iyer, Pipit Kalbarini, John Quirein