泡酸解卡技术在塔中11井的应用与认识

Application of acid soaking to release stuck pipe technology in Well Tazhong-11 and relevant understanding

塔中11井钻遇了两个漏层和一个高压层,同一裸眼内存在多个不同的压力系统。钻井复杂使得钻井液性能变差,钻井液携砂性变差、滤饼摩阻增大增加了发生卡钻事故的概率。钻井过程中发生了2次卡钻事故,由于卡钻地层为碳酸盐岩储层,借鉴试油、修井的酸化技术来解除卡钻事故。实践表明,泡酸解卡工艺是一种解除碳酸盐岩储层卡钻行之有效的方法,还利于储层保护,但能否在大漏失、高套压、高含硫油气井运用及泡酸解卡对后续作业有何影响,需要进一步分析研究。

Well Tazhong-11 encountered two leakage zones and one high pressure zone, and there were several different pressuresystems in one open hole. The drilling complexities made the drilling fluid properties become poor, and the deterioration of sandcarrying property of drilling fluid and increase of filter cake drag increased the probability of occurrence of pipe sticking. Pipe stickingoccurred two times during drilling. The sticking formation was carbonate reservoir, so the acidization technique which is used in oil testand downhole service was used to release the pipe sticking incident. Practice shows that the technique of acid soaking to release stuckpipe is an effective means of releasing pipe sticking in carbonate reservoirs, and it is also favorable for reservoir protection and hasgood economic benefits and high technical feasibility. But further analysis and research need to be conducted to its use in oil/gas wellswith large leakage, high casing pressure and high sulphur content and the effects of acid soaking to release stuck pipe on subsequentoperations.