The Sensitivity Analysis of Parameters for In-Situ Combustion
Chen Junbin(1),Xiao Shuqin(1),Zhou Fangde(1,2),Zhang Rongjun(1)
(1 Xi'an Petroleum Institute, Shaanxi, 710065) (2 Xi'an Jiaotong University, 710049)

Abstract: According to hydrocarbon reservoir percolation theory and combustion theory, and on base of oil displacement mechanism of in-situ combustion, the mathematical modeling is set up. The dry combustion is compared with the wet one by using the numerical method. The conclusion is drawn that the effect of the wet combustion is better than that of the dry one. In view of the characteristics of the wet combustion, through the analysis sensitivity of the corresponding parameters, the relevant conclusions are drawn: (1)the steam zone oil displacement is an important mechanism in the process of in-situ combustion; (2)with water-gas ratio increase, the region of oxidation reaction expands. The n the temperature of zone oil becomes low and the velocity of convective front increases. So it accelerates the conduction of heat convection and enhances oil displacement efficiency; (3) with oxygen utilization decrease, the region of oxidation reaction expands, the temperature of zone oil becomes low, the air quantity needed for burning one cube of oil sand increases and the velocity of convective front decreases. As a result, oil displacement efficiency almost keep constant; (4) with the amount of injection air increase, the region of oxidation reaction expands, the temperature of zone oil rises, the velocity of combustion front increases and the velocity of convective front increases. So it accelerates the conduction of heat convection and enhances oil displacement efficiency.
Keywords: in-situ combustion, mathematical modeling sensitivity analysis.