Tuning of an EOS model and generation of Black-oil PVT tables for a gas field in Tanzania, here named R reservoir, are presented. The Soave-Redlich-Kwong equation of state was tuned using experimental data and PhazeComp software to obtain the EOS model which represents fluid behavior change in the R reservoir. A contribution is provided in a relationship between specific gravity and molecular weight, which is a modified form of Soreide equation for C7+ characterization. Constants of the equation are determined using linear regression to fit experimental data. A residual oil in the reservoir is recognized using EOS calculation; PVT data generated in this paper can be used to study its potential to condensate blockage and well deliverability. Gas and oil PVT tables are generated for saturated and undersaturated condition, they can be used in reservoir simulation of R reservoir.EnPe 2013-2019 project no. 25135305