Analysis And Variation Tendency Of Produced Fluid In Simulation In-Situ Combustion

This work,carried out using sandstone outcrop and glutenite outcrop,was focused on the component and its changes of produced fluids before and after simulation ISC under different air injection fluxs or pressures.Using column chromatography to separate group composition of crude oil,and extracting the oil from produced fluid.The chemical compounds of produced gas and fluid were identified by GC and GC-MS,and its condition parameter had been optimized.N₂,O₂,CO₂,CH₄,C₂H₆,C₂H₄,c-2-C₅H₁₀,et al,Saturated hydrocarbons,benzene and naphthaline compounds were detected.With the increase of air injection flux,the quality of produced liquids and oil from sandstore and glutenite oil sand ISC increased and then decreased,and a maximun liquids quality at an air flux of 2.5 L/min was obtained,respectively.At the same air injection flux,the content of residual group components after ISC was minimum.The produced liquids quality of sandstore oil sand increased with the rising of pressure as a whole,and a maximum value at a pressure of 2.0 MPa;The produced oil quality of glutenite oil sand was increasing with the rising of pressure,but it made little contribution to improving oil production when the pressure was higher than 2.0MPa.Overall,the larger amount of produced oil,the lighter oil was,after analyzing the carbon number rule of saturated hydrocarbon.Some aromatic hydrocarbon had a good relationship with the quality of produced oil,It is to a certain degree that the proportion of naphthaline compounds in produced oil can be used as indicators to evaluate the oil yield.Methylnaphthalene proportion showed a negative relationship with the quality of produced oil,a large amount of methylnaphthalene indicate that displacement of oil is inadequate.CO₂,N₂,O₂,some saturated hydrocarbons（CH₄,C₂H₆,C₃H₈,et al）and unsaturated hydrocarbons（C₂H₄,C₃H₆,et al）were detected in produced gas.Under the experimental conditions,when the air flux was 2.5 L/min,and the pressure exceeded 2.0 MPa,The concentration of O₂ and CO₂ changed smoothly,combustion of ISC can be stabile.Alkane and alkene were detected in the produced gas shows that there are pyrolysis reactions and dehydrogenation reactions along with the combustion of ISC.The research on fluid component and its changes before and after simulation ISC can provide theoretical foundation for field test,evaluating the underground situation of oil combustion,and also controlling the combustion process.