| Conventional oilfield development technology and means cannot effectively extract heavy oil,ultra-heavy oil and extra-heavy oil from the reservoir.The above problems can be effectively solved by using the technology of burning oil layer.The high viscosity characteristics of heavy oil in Block D bring difficulties to its development and exploitation.In-depth understanding of the physical properties of heavy oil in Block D and the combustion characteristics and applicability of heavy oil in the process of fire flooding can better guide the field operation.In this paper,the basic physical parameters of heavy oil in Block D are measured by instruments,and the causes of high density and high viscosity of heavy oil in Block D are analyzed.Secondly,the use of tube furnace macroscopic simulation of each stage of burning oil layer,heavy oil oxidation law,combustion characteristics.Finally,the one-dimensional combustion tube device is used to further simulate the heavy oil fire flooding process,and the characteristic parameters of different combustion stages of the burned oil layer under different conditions are studied to determine the combustion state and applicability in the fire flooding process.The results show that:（1）The viscosity at 50℃is 341.25 Pa·s and the density is 0.998g·cm-3,which belongs to super heavy oil.The hydrocarbon distribution of crude oil is mainly concentrated in C20～C35.The stronger the intermolecular dispersion force,the higher the viscosity of heavy oil.（2）There is obvious oxidation reaction at low temperature oxidation stage;in the fuel deposition stage,the aromatic hydrocarbon is deoxidized to produce coke;during the high temperature oxidation reaction stage,the coke began to crack and burn;（3）Preheating temperature can effectively improve the low-temperature oxidation degree of heavy oil and ensure the smooth occurrence of high-temperature oxidation.Injection pressure affects the overall oxidation degree and then the combustion effect of heavy oil.The oil displacement efficiency of different reservoir porosity is about 84%.Porosity has no obvious effect on oil displacement efficiency,only affects the contact between heavy oil and oxygen.Different density of crude oil,oil displacement efficiency is about 86%.Density has no obvious effect on oil displacement efficiency.（4）The combustion in-situ technology is applied to Block D reservoir to improve preheating temperature and increase injection pressure,and the combustion front can expand smoothly to the output well.Under the condition of ensuring air demand,low porosity reservoirs and low density reservoirs also have the applicability of implementing the technology of burning oil reservoirs. |
