Study on Phase Transition and Gas Deviation Coefficient of Natural Gas with High Carbon Dioxide Content

It is the basic research subject that analyzes and calculate the law and numerical value of phase change and gas deviation coefficient of natural gas with high-CO 2 content in the process of safe and effective development of gas reservoirs, which is obtained by high-pressure physical properties PVT (Pres-sure-Volume-Temperature) experiments and different calculation methods calculations. Aiming at natural gas with high-CO 2 content in the Dongfang gas field, the phase change characteristics and physical parameters of different PVT samples are simulated and tested by Chandler 3000-GL analyzer and PVT SIM software. The experimental data shows that the phase state of natural gas with different content of CO 2 has not changed in the study range. At the same time, the deviation coefficient calculated by different calculation methods (DPR, DAK, BB, HY, Gopal) are compared with the experimental data, and the applicable scope of different calculation methods are obtained. The results show that the improved Gopal has high accuracy and is suitable for the calculation of the deviation coefficient of natural gas with high-CO 2 content under high temperature and high pressure in the Dongfang gas field.