Indoor Research Of Paraffin-Base Crude Oil Fire Flooding's Character

Distribution of paraffin-based crude oil(high solidification point oil)is very extensive.Traditional water flooding to exploit paraffin-base crude oil will face a variety of problems.Combined with the characteristics of the block,to develop new enhanced oil recovery technology for paraffin-based crude oil reservoir is necessary.Among domestic paraffin-based crude oil reservoir,Shenyang reservoir owns crude oil with high solidification point and have multi-reservoir type,so the development of Shenyang reservoir is representative.This paper is based on shen625 buried hill reservoir in Shenyang reservoir and to explore the feasibility of improving the recovery rate of paraffin base crude oil with air injection.On the basis of shen625 reservoir conditions,analysis shows that using air injection to replace water flooding is feasible in theory.The pilot experiment further explained that the application of air injection development effectively reduced the comprehensive decline of reservoir and water content,what's more,the output is stable and rising.Next stage's research we will do some indoor experiment to get more characteristics of paraffin-based crude oil development using fire flooding.In this paper,we use TG and ARC to study the oxidative exothermic properties of shen625 paraffin-based crude oil,and the oxidation kinetic parameters also were obtained.The results show that the exothermic character of the oxidation of shen625paraffin-based crude oil is to release a large amount of heat in the low temperature stage(300°C under normal pressure and 230°C under 5MPa reach the peak temperature)and the peak is four times the typical thin oil in a section of the haita reservoir,while the heat release in the high temperature stage is low,and the peak is 1/2 of the typical thin oil.We use in-situ combustion one-dimensional physical simulation experiment(combustion tube experiment)to obtained in-situ combustion parameters,the temperature of the burning front,and to probe into the stability of burning front.In addition,we will study the oil components and ventilation's influence to fire flooding.In this experiment,we observe that the expansion of burning front is stable,and the burning front temperature is maintained between 300 to 350?.During the experiment,no oxygen exists in the exhaust.All this proved that stable burning front could be formed in low temperature range during the experiment.Base on experimental data,the oil displacement efficiency is as high as 76%and the air oil ratio is 264.29 m~3/t.The paraffin-based crude oil in-situ combustion has very high oil displacement efficiency and low air oil ratio.Through comparative experiments,paraffin-based crude oil is proved to achieve a stable fire-flooding process easier than ordinary thin oil(low wax-containing).