Development Of In-situ Combustion Catalyst And Experimental Research Of Mechanism

In-situ combustion is an important thermal recovery method to enhance reservoir recovery.It have the obvious advantages compared with other methods of thermal recovery.In in-situ combustion development process,coke which cracking in the reservoir is the fuel to maintain the combustion front continues to burn.This method rely on the thermodynamic and other comprehensive driving force work together to achieve the purpose of improving oil recovery.But in-situ combustion experiment often appear failure phenomenon due to the complicated displacement mechanism.One of the key factor of success for in-situ combustion experiment is the amount of fuel consumption(also known as the precipitation amount of fuel and coke amount),it may cause bad burning effect when the amount of fuel consumption is low.The amount of air consumption is the key factor influencing the economy of in-situ combustion.The in-situ combustion experiment need a lot of air to maintain burning when the amount of fuel consumption is higer.So how to improve the utilization rate of oxygen,and save the economic cost is the important issue to consider for in-situ combustion.This paper research the nanometer particle catalyst suitable for the in-situ combustion development and analyse the optimal parameters of the catalyst.Modified the nanometer particle catalyst surface by oleic acid.This method enhance its dispersion in the oil phase and improve the catalytic efficiency.Comparative analysis the viscosity reduction effect of modified nanoparticles,nanoparticles catalyst,catalyst oil soluble metal catalyst through the indoor experiment and found that the modified nanoparticles particle catalyst modifie the crude oil viscosity obvious.This catalyst realize homogeneous catalysis.The catalyst preparation method have be provided,it have the characteristics of low cost and high catalytic efficiency.Thermal analysis method of crude oil is the important way to study the process of oxidation of crude oil.This paper study the thermal analysis of two kinds of oil sands by using analysis instrement.The oil oxidation process is divided into four stages through the TG/DTG and DSC curve.Both kinds of oil sands' s heat quantity of low temperature oxidation reaction is very low,and heat quantity rely on the high temperature oxidation.Calculate the each stage's activation energy of oil sands by FWO method.Observe the DSC curve,it is obviously that curve show bimodal trend,the heat quantity of low temperature oxidation increase quickly after adding catalyst.The temperature range of each stage of oil sands A and oil sands B moved towards the lower temperature zone,and the activation energy of each stage also reduced.Determine the influence factors of the curde oil's low temperature oxidation reaction and coking reaction is the important step to study the mechanism of in-situ combustion.Temperature is the main influence factor of tail gas content and SARA content of oil after low temperature oxidation.The rise of temperature benefit the add oxygen reation and decarboxylation in low temperature oxidation.After adding the catalyst,it promote the rate of low temperature oxidation reaction.And the catalyst modified the oil.The amount of light component(saturates hydrocabon and aromatic hydrocarbon)increase and the amount of heavy component(resin and asphaltene)decline.Accoring to the result of oil sands coking experiment,the coking mechaism of oil sands divide into two classes,oxidation coking and free radical polymerization coking.At low temperature is given priority to with oxidation coking,at high temperature is given priority to with free radical polymerization of coking.The oxygen content and temperature are the main factou that affect the amount of coking oil sands.Catalyst play a dule role of this process,it modified the crude oil and metal ions on the coking reaction play a catalytic role.The amount of coking decline after adding the catalyst.On the basic of the in-situ combustion tube laboratory experiments,develop two groups of in-situ combustion tube laboratory experiments by adding catalyst.Comparative analysis that,it decrease the combustion time of experiment and after increase the oxygen utilization rate significantly after adding catalyst.The oil A's oxygen utilization ratio increased by 6.78% and oil B's oxygen utilization ratio increased by 5.98%.Catalyst also improved the combustion front temperature and combustion front advance speed.In terms of recovery rate,recovery efficiency of oil A increased by 4.16%,the recovery of oil B increased by 3.71%,and the crude oil's viscosity and density is lower after experiment.Finally accoring the effect of the fuel consumption,combustion front advance distance and velocity,average temperature of the combustion front,air oxygen consumption and utilization analyzed the three key parameters,namely: gas injection speed,preheat temperature and sand grain size differential effects on fire to reservoir development effect.