The Mechanism Research On Steam Distillation For Thermal Recovery In Heavy Oil Reservoir

Thermal recovery is the main method of heavy oil development,water was used as the heat transfer medium during the steam stimulation,steam drive and steam assisted gravity drainage(SAGD).After high temperature steam injected,the reservoir rock and fluid were heated up,steam distillated the crude oil in the pores of the rock,and a part of the crude oil composition was brought out.Steam distillation is one of the main mechanisms of the thermal recovery of heavy oil.This article did physical experiments of crude oil steam distillation at high temperature and high pressure.The result shows that with the increase of superheat,the volume of distillation yield and the rate of distillation yield growth become bigger and bigger.This article also did a research about the methods which can calculate the steam distillation of crude oil,discussed the accuracy of SRK,PR equation of state and an analytical model proposed by Northrop and Venkatesan.After analysis,it shows that the residual oil become more heavy and thick after steam distillation.It can be found out that with the increase of steam injection,the composition of oil fraction become more heavy by analyzing the oil fraction.Compared the results that calculated by SRK and PR equation of state with experimental data,the result shows that neither SRK nor PR equation of state could calculate the steam distillation of crude oil accurately.But it shows a accuracy result when use these two equation to calculate the vapor liquid equilibrium in a system which contains only hydrocarbon.The analytical model proposed by Northrop and Venkatesan was used to calculate the steam distillation,compared the results with experimental data,found out that NV model is accurate at predicting the mass of oil fraction,but bad at predicting the compositions of oil fraction.