水平井泡沫流体冲砂技术研究及应用

Research and application of sand-flushing with foam fluid for horizontal wells

李宾飞 李松岩 李兆敏 李良川

LI Binfei LI Songyan LI Zhaomin LI Liangchuan

中国石油大学石油工程学院，山东东营　257061 冀东油田公司钻采工艺研究院，河北唐山　063004

College of Petroleum Engineering in China University of Petroleum, Dongying 257061, China CNPC Jidong Oilfield, Tangshan 063004, China

水平井冲砂作业时由于地层压力较低冲砂液漏失严重，泡沫流体冲砂技术可以有效减轻低压水平井的漏失问题，提高冲砂效率。通过实验和数值模拟方法研究了泡沫流体的携砂能力，得到了泡沫流体的携砂规律，并进行了现场应用。研究结果表明：当泡沫特征值为0.85时泡沫流体的黏度达到最大值1.14 Pa·s，直径为0.5 mm的砂粒的沉降速度为10-4~10-3 m/s，几乎可以悬浮在泡沫中；在接近水平的环空管道，泡沫流体的携砂性能远大于混气水和水的携砂性能，泡沫流体更适合于水平井的冲砂洗井。现场应用实例证实了泡沫能有效防止地层漏失，顺利建立起油套循环，作业后产量有较大幅度的增加，泡沫流体冲砂洗井技术是清除低压水平井井底出砂的一项有效措施，对现场具有指导意义。

Sand-flushing with foam fluid can effectively reduce leakage of flushing fluid in horizontal wells with low pressure. Sand carrying ability of foam fluid is studied by experiment and numerical simulation. When foam quality is 0.85, the maxmum of viscosity of foam fluid is 1.14 Pa·s. Falling velocity of sand with diameter 0.5 mm is from 10-4 m/s to 10-3 m/s. The sand could nearly suspend in foam fluid. In the annular pipeline closing to horizontal well, sand carrying ability of foam fluid is much better than that of aerated water and water, and it is especially suitable for sand cleanout of horizontal well. It can be seen from site applications that sand cleanout with foam fluid could prevent formation from leakage, and set up circulation between casing and tubing effectively. Oil production can be recovered soon after sand cleanout operation, and oil production rate can be improved. Sand cleanout with foam fluid is an effective method to remove bottom-hole produced sand of horizontal wells.