Experimental Study Of Heavy Oil Low-temperature Oxidation Characteristics And Influential Factors Of Spontaneous Combustion

At present,heavy oil reservoir(Xinjiang,Liaohe)exploitation in China has entered the pilot test phase of combustion drive andpre-air injection technology was carried out based on steam injection.However,due to the relatively low reservoir temperature of each development block,thus to reach reservoir spontaneous ignition temperature requires promoting reservoir temperature,original water saturation of different heavy oil reservoirs varies greatly,and clay mineral content distributed randomly.Thus it is essential to accelerate the reaction rate of heavy oil and oxygen,but even with costly and complex process,outside interference effect is still not significant.Therefore,the study of clay minerals and water saturation on heavy oil low-temperature oxidation rate and the heating rate changes in the oxidation reaction process has important economic significance.The thesis focuses on the influential factors on the low-temperature oxidation rate and heating rate through indoor static simulation experiment.High temperature high pressure reactor were used to study the effects of different water saturation on heavy low-temperature oxidation rate and heating rate,the results show that it promotes heavy oil low-temperature oxidation heating rate when heavy water saturation was30% and the amount of CO2 and CO decreases with water saturation increases.Orthogonal test method was used to determine the best technological conditions that promote low-temperature oxidation heating rate and improve heavy oil fluidity,the results show that high air-fuel ratio?30% of water saturation with the temperature of 180 ?are the best.Influential degree ranks are air-oil ratio,water saturation,temperature;High temperature high pressure reactor was used to study the effects of different types of clay minerals on heavy low-temperature oxidation rate and heating rate,the results show that heating rate?oxidation rate and carbon bond release reaction rate have improved significantly in porous medium,the catalytic ability of various clay minerals is as follows: montmorillonite > chlorite > kaolinite;Then orthogonal experiment analysis was used to determine influential degree of each factors on heavy oil low temperature oxidation process,the ranks are montmorillonite,temperature and air-oil ratio.The best technological conditions that promote low-temperature oxidation of heavy oil reservoirs that have high content of montmorillonite during the pre-air injection process was toraise reservoir temperature to 180 ?,15% of clay mineral concentration,high volume air injection.