Flow Behavior of Daqing Waxy Crude Oil under Simulated Pipelining Conditions

Abstract

Daqing oilfield is the largest oilfield in China. This crude oil is a typical waxy crude oil, with a wax content of 26% and a gel point of 32 °C. Flow behaviors of waxy crude oils at temperatures near the gel point/pour point are vital for both pipeline hydraulic calculation and evaluation on restartability of a shutdown pipeline. In this study, experimental simulation was conducted by using a stirred vessel with the energy dissipation of viscous flow as the shear simulation parameter. Crude oil specimens were taken from the stirred vessel at different temperatures during flow simulation, and the DSC (differential scanning calorimetry) curves and rheological properties, such as viscosity, gel point, yield stress, and thixotropy, were measured. The viscosity under simulated pipelining conditions was found to be much less than that measured under quiescent cooling conditions, and the gel point decreased with decreasing temperature of sampling, i.e., the end temperature of the dynamic cooling process. The DS...