欠平衡泡沫钻井液技术在窿14井的应用

窿14井是青西油田窟窿山构造的一口重点工程探索井.该井为配合在1358～2670 m的欠平衡空气钻井实验,使用了泡沫欠平衡钻井液技术.通过室内研究,优选出了适合在该地区使用的各种处理剂,并通过调整处理剂加量优化设计泡沫钻井液配方.评价试验表明,该配方泡沫钻井液发泡率高、稳定时间长、抗温性好、抗污染能力强、抑制能力强、腐蚀性小.现场应用表明,所使用的泡沫钻井液性能优良,满足了空气钻井方式下携岩的要求,对钻具腐蚀性小,井壁稳定能力好,在地层持续出水的情况下仍保证了井壁的稳定性,应用井段无坍塌事故.

Application of Underbalanced Foam Drilling Fluid in Long-14 Well

The well of Long-14 was a major exploration well for the structure of Ku Long-shan in Qingxi oilfield.The foam fluid was employed for underbalanced drilling in the section from 1358 m to 2670 m.The available additives and the optimized formulation were determined by a great quantity of laboratory experiments.The data from evaluation tests indicated that the optimized foam fluid exhibited favorable foamability,temperature resistance,contamination protection and inhibition and had a long stability period and a slight corrosiveness.The field trials demonstrated that the foam fluid developed met the requirement of cuttings carrying for the air drilling and can still maintain the hole stability even if continuous water production was encountered.No caving occurred.