泡沫酸酸化技术及其在气井酸化中的应用

在常规酸化过程中，对于多层非均质地层而言，由于渗透率的差异，酸液主要是进入其中的高渗透层，低渗透层或堵塞严重的地层就不能进酸或进酸太少，这影响酸化效果。针对上述问题，对泡沫酸酸化技术进行了研究；通过室内实验筛选出了耐酸耐盐的起泡剂DY-1+SJ-8和稳泡剂KMS-2，并对不同起泡剂浓度下的泡沫酸性能进行了评价，确定了其使用浓度；在此基础上进行了泡沫的岩心分流实验，实验结果表明泡沫流体可以增加低渗透岩心的分流量，减少高渗岩心的分流量，使泡沫流体在不同渗透率岩心内均匀推进，基于此原理，泡沫酸酸化可以增加中低渗透层的酸液注入量，减少高渗层的吸酸量，提高酸化效果。泡沫酸酸化技术在中原油田气井酸化中获得了成功，增产效果显著，目前已被中原油田作为气井酸化的推荐工艺加以推广应用。

FOAMED ACID ACIDIZING AND ITS APPLICATION ON GAS WELLS

In conventional acidizing in heterogeneous reservoirs, the remarkable difference in acid intake of different permeability formations will influence the efficiency of acidizing. To resolve these problems, this paper deals with the technology of foamed acidizing. The anti-salt and anti-acid foamer DY-1+SJ-8 and foam stabilizer KMS-2 were selected, then their performance under different foamer concentration condition was evaluated and the proper concentration was determined. Thereafter the diversion experiment of foamed acid through the parallel core was conducted. The results of the experiment indicate that foamed acidizing technology can increase the acid intake of low-permeability formation and reduce that of high-permeability formations, keeping the balance of the acid intake of different permeability formations so as to improve the acidizing effect. The technology was successfully applied in Zhongyuan oil field with remarkable outcome increase, and was popularized as a recommendable acidizing technology of gas wells.