海底混输管道输送油气时常伴随砂粒,在重力沉降因素作用下,砂粒可能沉积在管道底部,减小流通面积,导致摩阻增大、管道输送能耗上升。基于OLGA软件建立海底混输管道油气混输携砂仿真模型,以某海底混输管道为研究对象,分析砂粒物性参数(砂粒径、砂粒质量分数和砂粒密度)、管道内径及流动参数(气体质量分数、流体质量流量和出口压力)对砂粒运移与沉积的影响。结果表明,砂粒沉积量与砂粒径、砂粒质量分数、砂粒密度、管径呈正相关,在悬浮流时,砂粒沉积量与休止角无关,但与孔隙度呈负相关;随着气体质量分数和流体质量流量的增加,砂粒流型将会经历静止床、移动床和悬浮流的变化;在悬浮流时,增大气体质量分数、流体质量流量及降低出口压力将会减少砂粒沉积量;在实际工程中,可通过提高流速除去砂粒沉积。研究结果为海底混输管道砂粒沉积的防护提供了理论支撑。

The multiphase transportation of oil and gas in subsea pipelines is often accompanied by sand particles. Under the action of gravity settling, sand particles may deposit at the bottom of the pipeline, reducing the flow area, resulting in increased frictional resistance and elevated energy consumption in pipeline transportation. Based on OLGA software, this paper establishes a simulation model for subsea multiphase oil-gas flow with sand transport. Taking a subsea pipeline as the research object, the effects of sand physical property parameters(including sand particle diameter, sand mass fraction, and density), pipeline inner diameter, and flow parameters(including gas mass fraction, total fluid flow rate, and outlet pressure) on sand transport and deposition are analyzed. The results show that the sand particles deposition is positively correlated with the sand particle diameter, sand mass fraction, sand density, and pipe inner diameter. In suspended flow, sand deposition is independent of the angle of repose but negatively correlated with the porosity. With increasing gas mass fraction and the fluid flow rate, the sand flow pattern transitions from stationary bed to moving bed and then to suspended flow. In the suspended flow, increasing the gas mass fraction and fluid flow rate, as well as decreasing the outlet pressure, will reduce sand particles deposition. In practical engineering, sand particles deposits can be removed by increasing the velocity to enhance sand-carrying capacity. The results of the research will provide theoretical support for sand deposition protection in subsea multiphase pipelines.