Experimental Study On Relaxation Frequency Effect On The Viscosity Reduction Of Heavy Oil

Heavy oil viscosity reduction by applying microwave is a new technology.The microwave frequency and material inherent relaxation frequency as the significant parameters will bring obvious effect on microwave process.This paper investigated the relaxation frequency influence law of the effects of microwave applied viscosity reduction process from two aspects of experiment and theory and providing reference and theoretical basis of the microwave energy maximum effect in heavy oil.Firstly,this research carried on a rheological compare experiment of microwave frequency and temperature's impact on the heavy oil viscosity decreasing effect under five different microwave frequency(27MHz?235MHz?470MHz?915MHz?2450MHz)and temperature range of 30?-70?.And then,collected the data of heavy oil complex permittivity and loss tangent under different frequency and temperature range(20?-70?).The microwave frequency and temperature influence law on heavy oil dielectric property is analysed.According to the complex permittivity data collected from experiment and the debye function,heavy oil “cole-cole” curve is provided,and obtained the range of peak relaxation frequency f_R.Finally,combined with experimental and theoretical study,analysed the influence of microwave thermal effect and non-thermal effect when microwave energy effected in heavy oil,and relaxation frequency influence law on microwave based heavy oil viscosity reduction is obtained.The main conclusions of this research were given as follows:(1)When oil sample temperature range is 30?~70 ?and microwave frequency range is 27MHz~2450MHz,under the same temperature,higher frequency will improve the viscosity reduce effect,meanwhile,under the same microwave frequency,lower heavy oil temperature will improve the viscosity reduce effect too.(2)When oil sample temperature range is 20?~70 ?and microwave frequency range is 235MHz~2450MHz,under the same temperature,higher microwave frequency will lead to the larger dielectric loss.When under the same microwave frequency,lower heavy oil temperature will lead to the larger dielectric loss.(3)In the oil sample temperature changing range of 20?~70?,range of peak relaxation frequency f_R is 3169~2570MHzMHz,which is chose as the preferred frequency band of microwave to reduce the viscosity of heavy oil.(4)The more microwave frequency close to the heavy oil relaxation frequency,the better viscosity reduce effect it has.(5)The effects of microwaves on heavy oil were influenced by the combined action of microwave thermal effects and non-thermal effects.