Abstract: The precipitation of wax and asphaltene has brought serious problems in production and petrochemical process of oil and gas. In order to mitigate the damage caused by the precipitation of organic solid, the research of solid precipitation and modeling, which can offer a basis for the production, transportation and petrochemical process for oil and gas, is necessary. The laser technique can test solid precipitatio at high temperature and pressure for a system of oil and gas. The thermodynamic model of oil-gas-solid phase equilibrium can be used in production efoil and gasas. well as solid precipitationmedeling in presssof gas injestionin which oil-gas-solid phase behavior conyersion occurs.

Key words: wax precipitation, experimental test, thermodynamic modeling