摘要
在钻井过程中,如果地层孔隙中流体的压力小于钻井液液柱压力,会发生地层被钻井液侵入,引起地层污染的后果。这会大大影响油气井的产能,我们只有理解和掌握钻井液渗滤的污染机理,才能有效的进行防治。在油气井投产之前,一般会采用酸化、压裂的方法解堵,为了确保解堵措施安全高效,需要精准地确定钻井液的伤害程度和侵入深度。数值模拟在研究钻井液渗滤问题上应用非常广泛。基于有限元的数值模拟的方法研究地层渗透率,泥饼渗透率和钻井时间对钻井液渗滤的影响。通过对相关算例进行分析,系统的概括出钻井液渗滤的影响因素。结果表明:地层渗透率越低,钻井液沿水平井筒渗滤越困难;泥饼渗透率越低,钻井液的侵入深度越小,钻井时间越长钻井液沿水平井筒渗滤越多,侵入的深度越大。
In the process of drilling, if the formation pore fluid pressure is less than drilling fluid column pressure, formation pollution caused by drilling fluid invasion will happen. This will greatly affect the capacity of oil and gas wells, the pollution mechanism of drilling fluid percolation must be understood and mastered in order to carry out effective prevention and control. Before the oil and gas well production, blockage removal methods of acidification and fracturing are usually adopted. In order to ensure blockage removal measures to be safe and effective, the damage degree and the invasion depth of drilling fluid need be accurately determined. The numerical simulation has been widely used in research on drilling fluid percolation. In this paper, based on the finite element method of numerical simulation, effect of formation permeability, mud cake permeability and drilling time on drilling fluid percolation was studied. Through analysis of relevant examples, the influence factors of drilling fluid percolation were summed up. The results show that, the lower the formation permeability, the more difficult the drilling fluid percolation along the horizontal wellbore; The lower the mud cake permeability, the smaller the invasion depth of drilling fluid; the longer the drilling time, the more the drilling fluid percolation along the horizontal wellbore, the greater the depth of invasion.
出处
《当代化工》
CAS
2015年第7期1515-1518,共4页
Contemporary Chemical Industry
基金
黑龙江省自然基金项目
项目号:A201201
关键词
钻井液侵入
水平井
地层污染
Drilling fluid invasion
Horizontal well
Formation pollution
