Qaiyarah oil field is characterized by its complexity due to its extra heavy oil reaching 16° API. Thus, building a systematic PVT model for this field at a specific range of temperatures is a powerful challenge for screening such reservoirs. The peng-Robenson equation of state model with up to six pseudo components was developed for the crude sample of the Qaiyarah oil field. This work represents the fingerprint for constructing a dynamic model for the field under study. The model also applies to the heavy oil reservoirs under splitting and lumping scenarios. This work suggests a lumping scheme to enhance the accuracy and CPU performance of compositional reservoir simulations. Therefore, the full components model (13 components) is lumped into a reduced number of pseudo components (6 components) to be utilized in the compositional fluid simulation. This study outlines the Peng-Robinson equation of state (EOS) to tune the data at a certain pressure range up to 400 psi. More specifically, various essential parameters have been trained to match the model results with the experimental data. Splitting processes of C6+ into four pseudo components, namely, HYP0_1, HYP0₂, HYP0_3, and HYP0₄ is added to the matching picture. Separately, justifying the critical properties introduced a better result of regression. The results showed an acceptable match for Bo with an error percent below 1%, while calculated oil viscosity deviated from measured values in different ranges against pressure variation.