Study On The Rule Of Thermal Recovery In Bohai Heavy Oil Reservoir

At present,the thermal recovery of heavy oil in Bohai oilfield is in the pilot test stage,which lacks basic reservoir fluid parameters.In this paper,the heavy oil reservoir in Bohai oilfield is taken as the object of study,and the laboratory simulation experiment is used to study the seepage law of Bohai heavy oil reservoir from two aspects of viscous fluid rheological characteristics and seepage characteristics.Through the study of this paper,the following results are obtained:(1)Bohai heavy oil has a strong temperature sensitivity,the experimental temperature increased from the formation temperature to 100?,120?,and the temperature of 140?,corresponding to the viscosity of ordinary heavy oil,extra heavy oil and super heavy oil,were lower than 100 mPa·s.(2)The Bohai crude oil rheological characteristics consistent with the rheological characteristics of Bingham fluid.The yield value of heavy oil is higher than 40?,and the temperature is below in the range of 10 Pa and above 70 below 1Pa.It shows that there is a great difference in fluidity of heavy oil at ?low temperature.(3)When hot water flooding,the super heavy oil infiltration interval is slightly larger than that of ordinary I-2 heavy oil,and the relative permeability value of super heavy oil is higher than that of ordinary I-2 heavy oil.(4)When the injection volume is in the range of 0-1.0PV,due to thermal expansion,the oil displacement efficiency of hot water flooding and steam flooding increases with the increase of injection quantity.When the injection volume exceeds 1.0PV,displacement plays a leading role at this time,the oil displacement efficiency decreases with the increase of injection rate.These results provide experimental basis for field application.