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 DUARTE, M.

Nova Friburgo

Congreso; CBTERMO 2019 (X Congresso Brasileiro de Termodinamica Aplicada); 2019

UERJ

Many decisions in the oil andgas industry, either technical or economic, as well as design of equipment,etc., depend on how the reservoir fluid will evolve in response to changes ofpressure and temperature during production and considering the different operationsin surface facilities. The results of compositional analyses and PVTexperiments from a sample of the reservoir fluid provide essential information forits modeling through and Equation of State (EoS). Nevertheless, and given thatonly the more volatile compounds are identified, such information needs to becomplemented with procedures for a default parameterization of the heavyfractions in the form of pseudo-components and then adjust some parameters ofthe thermodynamic model to obtain an accurate description of the PVT behavior.As a continuation of previous studies, in thiswork we complete an analysis of how different parameters affect the predictedphase behavior of two selected fluids, a gas condensate and a volatile oil, inparticular phase envelopes and constant mass expansion (CME) experiments. Thisinformation allows understanding the way in which each parameter influences theprediction and how each of them should be adjusted, if required, in order tomatch each type of data. Based on those effects, a strategy is proposed fortuning some key fluid parameters to reproduce this typically availableexperimental information for reservoir fluids. In order to include the effectof the third parameter, the sensitivity analysis is made with the RKPR EoS, butthen the strategy is applied also with the Peng-Robinson (PR) EoS. Theperformances of both models are analyzed based on predictions for the liquiddrop-out curve in the case of the gas condensate and of differential liberationexperiment for the volatile oil, besides considering the whole CMEpressure-volume curve in both cases.