Effect of Characterization of C7+ and C11+ on the Prediction of PVT Properties of the Black Oil System

Abstract

Experimental data of ‘PVT properties of some samples of black oil were obtained and matched with the prediction of equation of state. Effect of C7+ and C11+ on the saturation pressure, relative volume, density, vapour Z-factor and gas formation volume factor were determined. Splitting of C7+ and C11+ was also carried out. The effect of splitting of both types of heavy ends on the PVT properties mentioned above were also determined. It was found that characterized C11+ when used in equation of state gave better prediction of fluid properties than using C7+. It was found thatsplitting of C7+ into pseudo component gave better prediction of saturation pressure than C11+ into pseudo component. It was observed that when pseudocomponents of C11+ are used in equation of state gave more error in the prediction of saturation pressure, relative volume, density, gas Z-factor as compared to the C7+. It was also found that more the number ofthe pseudocomponent more will be error in the prediction of saturation pressure. Peng Robinson equation of state (PR EOS) was used to simulate constant composition expansion (CCE) and differential liberation (DL) experiments. It was observed that capability of PR EOS to simulate CCE experiment is better than the differential liberation experiment. The error analysis in the prediction of PVT properties mentioned above is also elaborated.