基于EDEM-Fluent耦合模拟高含硫气藏地层硫沉积

Coupled simulation of sulfur deposition in sour gas reservoir formation based on EDEM-Fluent

溶解在酸性气体中的元素硫会随着地层压力的降低从气体中析出,析出硫微粒的沉积会对地层造成严重伤害。以往对于地层孔隙中硫微粒的沉积与否,主要是通过研究其所受合力情况来判别,忽略了硫微粒的具体形状、碰撞、聚集等因素。因此,针对井筒附近地层发生硫沉积的高含硫气藏,利用EDEM-Fluent耦合方法模拟研究孔隙中硫的沉积规律。研究结果表明:同样大小的微粒,由于存在碰撞、凝聚等作用力,所受合力不同,产生了不同的运动规律;在流动方向上,硫沉积量呈递增趋势;硫微粒在孔隙中的同一位置沉积量,会随着时间的增加逐渐增大;离孔隙壁面越近的硫微粒,沉积越牢固,越不容易被气流带走;硫微粒浓度在纵向从上到下依次增加;随着气体中硫质量分数的增加,硫沉积速率也增大;孔隙突然扩大或缩小,硫沉积呈现出不同的规律。

The elemental sulfur dissolved in acid gas will separate when formation pressure drops,and the precipitation of sulfur particles will cause serious injury.In the past,the decision of sulfur particles deposited in the pores was mainly by the composition of forces,which ignored the specific shape of the sulfur particles,collision,aggregation,and other important factors.Therefore,for the problem that sulfur deposition occurs in the near wellbore formation in sour gas reservoir,the law of sulfur deposition in the pores was studied using EDEM-Fluent coupled modeling.The results show that： for particles of the same size,due to the collision and agglomeration forces etc.,different forces are caused,which results in different sports law; in the flow direction,the amount of sulfur deposits into an increasing trend; the deposit amount of sulfur particles will increase as time increases in the same location in the pores;the closer the sulfur particles from the pore wall,the stronger the deposition,the more difficult it is to be taken away by the gas flow; the concentration of the sulfur particles tends to increase from top to bottom in the longitudinal direction; the sulfur deposition rate increases with sulfur concentration increasing in gas; sudden expanding or narrow pores exhibit different sulfur deposition law.