Quantifiable Characterization of Low-temperature Rheology Behavior of Daqlng Crude Oil

In allusion to the requirement of Northeast Pipeline Networks to transport Daqing Crude Oil at low-throughput under the condition of safety operation, mathematical model of rheology behavior parameters of Daqing Crude Oil about set point, viscosity (apparent viscosity), yield stress related to heat history and shear history at pipeline transportation is established based on theoretical analysis of rheology and results of pipeline transportation simulation experimental research.Houska thixotropic model of incompletely reversible parameters of crude oil is introduced that is suitable for describing the thixotropic behavior of Daqing Crude Oil.Through experiment, parameters of thixotropic model of Daqing Crude Oil are obtained under the condition of pipeline transportation of TieDa Oil Pipeline and QinJing Oil Pipeline.The research achievements are applied to the low-throughput operation characteristics and safety assessment of Daqing Crude Oil Pipeline.Based on the method of flow safety and quantitative assessment for hot oil pipeline, the minimum safety inlet temperature of TieQin Oil Pipeline at different throughputs is obtained.