In heavy crude oil, high viscosity exerts a large drag force on sand particles. In this paper, the influence of heavy oil viscosity on the natural settlement of sand is studied, and two models of settling velocity are established. These models have many practical applications such as calculating the time for sand to settle and designing separators and setting tanks. To visually observe and record the sand settlement process, transparent industrial white oil is used to simulate heavy oil in this study. The settling of individual particles of sand under the gravity force is experimentally studied, and drag coefficients are determined. Various models are used to predict drag coefficients of spherical and nonspherical particles, and predicted values are compared with experimental values. The results are analyzed to explore the influence of sand particle morphology on the prediction of drag coefficients. Two dimensionless settling velocity models are established and used to analyze the behavior of sand particles in heavy oil; the results prove the reliability and applicability of the settling velocity model. In this study, a nonspherical particle drag coefficient model has no advantage over a spherical particle drag coefficient model in terms of prediction accuracy. Thus, it is not necessary to consider the influence of sand particle morphology when making predictions of the characteristic parameters of sand sedimentation in heavy oil. An explicit settling velocity model is established on the basis of the Brown-Lawler drag coefficient model, and its prediction accuracy is greater than 90% for the settlement velocity of sand in heavy oil.

在重质原油中，高粘度对砂粒产生很大的阻力。本文研究了稠油粘度对砂石自然沉降的影响，建立了两种沉降速度模型。这些模型具有许多实际应用，例如计算沙子沉降的时间以及设计分离器和沉淀池。为直观观察和记录砂沉降过程，本研究采用透明工业白油模拟稠油。对重力作用下单个砂粒的沉降进行了实验研究，并确定了阻力系数。各种模型用于预测球形和非球形颗粒的阻力系数，并将预测值与实验值进行比较。分析结果，探讨砂粒形态对阻力系数预测的影响。建立了两个无量纲沉降速度模型，用于分析稠油中砂粒的行为；结果证明了沉降速度模型的可靠性和适用性。在本研究中，非球形粒子阻力系数模型在预测精度方面与球形粒子阻力系数模型相比没有优势。因此，在预测稠油砂沉降特征参数时，无需考虑砂粒形态的影响。在 Brown-Lawler 阻力系数模型的基础上建立了显式沉降速度模型，