PARAMETRIC TUNING OF RESERVOIR FLUIDS: A STRATEGY FOR MATCHING PSAT AND COMPLEMENTARY INFORMATION FROM A CONSTANT MASS EXPANSION EXPERIMENT

FIOROTTO, MARIANO; PISONI, GERARDO O.; CISMONDI, MARTÌN

Nova Friburgo

Congreso; X Congresso Brasileiro de Termodinâmica Aplicada (CBTermo) e VI Escola de Termodinâmica; 2019

Universidad del Estado de Río de Janeiro

Many decisions in the oil and gas industry, either technical or economic, as well as design of equipment, etc., depend on how the reservoir fluid will evolve in response to changes of pressure and temperature during production and considering the different operations in surface facilities. The results of compositional analyses and PVT experiments from a sample of the reservoir fluid provide essential information for its modeling through and Equation of State (EoS). Nevertheless, and given that only the more volatile compounds are identified,such information needs to be complemented with procedures for a default parameterization of the heavy fractions in the form of pseudo-components and then adjust some parameters of the thermodynamic model to obtain an accurate description of the PVT behavior. As a continuation of previous studies, in this work we complete an analysis of how different parameters affect the predicted phase behavior of two selected fluids, a gas condensate and a volatile oil, in particular phase envelopes and constant mass expansion (CME) experiments.This information allows understanding the way in which each parameter influences the prediction and how each of them should be adjusted, if required, in order to match each type of data. Based on those effects, a strategy is proposed for tuning some key fluid parameters to reproduce this typically available experimental information for reservoir fluids. In order to include the effect of the third parameter, the sensitivity analysis is made with the RKPR EoS,but then the strategy is applied also with the Peng-Robinson (PR) EoS. The performances of both models are analyzed based on predictions for the liquid drop-out curve in the case of the gas condensate and of differential liberation experiment for the volatile oil, besides considering the whole CME pressure-volume curve in both cases.