关键词: 原油长输管道, 常温输油, 降凝剂

Abstract: The paper covers a technological research on pour point depressant used for long-distance transportation of crude oil and describes a field test on the Ma-Hui-Ning pipeline.The pour point of Maling crude oil is decreased from 16 degree to -2 degree C and 5 degree C after addition of 50 ppm depressant, the viscosity was decreased from 133 mPa·s to 122.7 mPa·s at a shear rate 11.5 s^-1.The conversion point at which Newtonian behavior changed into non-Newtonian one is also decreased from 24 degree C to 15 degree C.In comparison with heated oil transportation at the same period, fuel consumption was reduced by 56%, the power consumption was reduced by 8%.The effect of treatment temperature, high shear rate and repeated heating on improving crude oil flowability at a low temperature was studied.The mixed transportation with the addition of Hongjing crude oil and restarting the pipeline in the case of shutdown were also observed and investigated.The ideal temperature of pour point depressant treatment should be the optimum temperature for heat treatment.The optimum amount for initial injection of pour point depressant can be determined from an aquation μ=μ₀+Ae^-Bq.Local heating and large pump rate flushing are not applicable for preconditioning the pipeline when pour point depressant is used for low temperature transportation of crude oil.The combination of addition of pour point depressant and heat treatment improve the low temperature flowability of crude oil to enable normal temperature transportation in Ma-Hui-Ning pipeline.