Modified Rock Typing Method for Carbonated Oil Reservoirs

Rock typing is one of the most important but controversial piece of reservoir characterization in which a specific class of reservoir rock will have a particular k-φ relationship, Pc curve and a set of relative permeability curves. Occasionally, rock typing is expected for static purposes such as reservoir estimation of initial oil in place; while usually, the purpose is to predict the dynamic behavior of the reservoir and preparing the development plans. Static rock typing is usually performed using the geological parameters, pores and throat sizes, petrophysical parameters and other instinct parameters of the reservoir for Flow zone indicator (FZI), Winland, and Lorenz methods. However, a particular and well-defined method is not available for determining the rock type and precisely classifying the reservoir rock into the groups. The introduced method in this paper is based on combining the Lorenz method with FZI classification. The optimum number of classes was determined by Lorenz method based on geologic framework and was characterized to use as an input in FZI method. The claim approval was investigated in one of Iranian oil reservoir.