水平井泡沫分流酸化数学模型及其数值解法

由于钻井过程中钻井液对储层的伤害,水平井的产能受到影响。酸化是一种常用的水平井增产措施,常规酸化存在地层进酸不均的问题;而泡沫酸化能有效地封堵高渗透储层,提高低渗透储层的渗透性,达到更有效的酸化增产效果。通过研究泡沫流体在水平井段流动和在油藏中的渗流特性,建立了水平井泡沫分流酸化数学模型,并对模型进行求解,得到了沿水平井段酸液的流量和压力的变化关系,以及沿水平井段流入地层泡沫酸量的变化规律。结果表明,沿水平井段流入地层的酸液量变化不大。因此,泡沫酸化能够解决地层进酸不均、解堵不均的问题,提高酸液利用效率,均匀改善受污染储层,提高受污染储层的渗透性,达到良好的均匀酸化的效果。

Mathematical model and numerial solution of foam diversion acidizing in horizontal well

Because of the damage of drilling fluid to reservoir in the process of drilling horizontal well, the productivity of horizontal well will be affected. Acidizing is a usual method of enhancing the productivity of horizontal well. There is one problem of general acidizing that acid distribution in the layer is uneven. Foam acidizing can effectively block the high permeable layer and enhance the permeability of low permeable layer, and the resuh of acidizing will be more effective. In this paper, through researching the seepage characteristics of foam fluid flow along the horizontal wells in the reservoir, the mathematical models of foam diversion acidizing are established and the solution is given. The variable relationship between acidizing fluid rate along the horizontal interval and pressure and the variable rule of foam-acid along the horizontal well are obtained. The result shows that the change of acidizing fluid rate is little along the horizontal interval. Consequently, foam-ac.id can solve the problems of acid moving and breaking down unequally in the reservoir and it also can enhance the availability of acidizing fluid, evenly improve the polluted reservoir and its permeability, achieving a good effect of acidizing.