A New Method For The Analysis Of The Phase State Characteristics Of The Tarim Near Critical Volatile Oil Reservoir

The phase characteristics of formation fluid is an essential part of reservoir research.The characteristics of the volatile oil in the phase state are different from those of the black oil,but the description of the characteristics of the volatile oil phase in the critical area is few,and the data in the oil area are poor.The essential volatile oil reservoirs with high wax in the critical area of the TLM area have the characteristics of a typical oil reservoir with high wax.On the basis of a large number of experimental data of PVT high pressure physical properties,this paper describes the empirical model prediction method for determining the physical parameters of the critical area of volatile oil with high wax,it also analyses and determines the main controlling factors of the phase flow parameters.A new empirical model is used to quickly predict the critical physical parameters of the fluid containing volatile oil reservoirs,and is verified by an example of the PVT experimental data supplemented by 12 layers of paraffin volatile oil fluid samples.Compared with the old empirical formula,the empirical model established in this paper has better prediction effect.In addition,the paraffin deposition of ZG166H has also been tested.The state equation was optimized by using the mathematical modeling software,and the wax deposition prediction of volatile oil was completed.Through this study,the following results have been obtained.(1)The applicability of the existing empirical formula in the TLM waxy volatile oil region is studied.It is found that the empirical formula can not be used to calculate the parameters such as bubble point pressure,viscosity,dissolved gas oil ratio,density and volume coefficient of TLM in the volatile oil region.Based on a large number of empirical formulas and data of TLM waxy volatile oil,a new correlation formula of related parameters has been established.(2)The correlation formula of the new physical parameters corrects the key parameters in the empirical formula to apply to the TLM reservoirs with high wax.In addition,the new correlation formula considers multiple factors including the key element of the fluid component,and compares the old empirical formula with the new correlation formula to predict the wax content more accurately and quickly.The advantages of the fluid parameters of the volatile oil reservoir.(3)Combining the experimental data and the calculation and Simulation of the PVTsim software,the PR state equation is optimized.The PR state equation is more suitable for the calculation of the phase state and the paraffin deposition of the TLM wax containing volatile oil reservoir.(4)The mole fraction and wax precipitation line of the gas-liquid-solid in the ZG166H are simulated and calculated at different temperatures and pressures,and the wax precipitation point of the ZG166H fluid is determined to be 29 centigrade.