Study On Profile Modification For Fire Flood In Thin Interbedded Heavy Oil Reservoirs

The oil reserve of the multilayered heavy oil reservoirs are abundant in Liaohe Oilfield,the viscosity of heavy oil are 1000 ~ 10000 mPa·s under reservoir conditions,and there are more 10 layers in the reservoir.It is easy to gas channeling in multilayered heavy oil reservoirs in fireflood process.However,it is difficult to meet the demands of fireflood multilayered reservoir in views of temperature endurance near the air injection well to the conventional profile control,such as gel and foam et al.Therefore,gas channeling and profile control of air injection wells in fireflood process for multilayered are discussed in this work.Firstly,variation of gas and temperature distribution are investigated based on numerical simulation of the typical well group of the fireflood reservoir,then technical requirements for air injection conformance are suggested for different stage in fireflood process.Secondly,practical profile control agents are selected to meet the demands of fireflood multilayered reservoir in views of temperature endurance,plugging strength and selectivity.Thirdly,the dynamic characteristics of air injection well in fireflood process is evaluated by numerical simulation.Finally,technological parameters of selective plugging are optimized for air injection wells of multilayered reservoir.It shows that gas channeling is inclined to occur in fireflood process for the heterogeneity of multilayered reservoir.The effect of blocking is well to the double fluid method,alcohol induced salt precipitation,steam induced salt precipitation and gel+ bentonite for the multilayered heavy oil reservoirs.It is applicable to the four profile modification methods,middle and later in the fireflood;while it can only be used to the induced salt precipitation,early in the fireflood;while it can only be used the alcohol induced salt precipitation and double fluid method,before the fireflood.