Uniform acidification technology and its application in horizontal wellAuthor(s): Zhang Hewen, Ding Yunhong, Zou Honglan, Yan Xuemei
In order to acidize whole horizontal well interval uniformly, temporary plugging technology was chosen as one of the most effective methods. Laboratory tests were also carried out to evaluate their diverting properties. The results show that clean self-diverting acid could increase its viscosity during reaction with carbonate, and which made it divert to other layers. And for fiber, it has good temporary plugging and degradable performance, which can meet the need of uniform acidification and low damage to oil reservoir. According to the analysis of fiber characteristic, some using principles were also given. This technology was applied on ten wells, and temporary plugging and diverting display could be clearly observed by observing pumping pressure change. Furthermore, final production rate after stimulated was increased obviously. All these results showed that this technology could get a better application effect in horizontal well acidification.