Abstract: Large-scale staged fracturing horizontal well has become the dominant development technology at Changqing Oilfield thanks to continual tight oil development at the oilfield. However, treatment of fracturing water and flow-back fluid is the main factor to impair renovation of horizontal well as the scale of fracturing is expanded. To solve this bottleneck, CQ-GNS twin nonionic surfactant for fracturing fluid thickener is developed to be used as core component of recoverable low-resistivity surfactant fracturing fluid system. This fracturing fluid system has a number of characteristics, such as free of residues, low damage, low resistivity, direct mixture and able to be directly recovered after flow-back and recycled when added with the same thickener. It is suitable for horizontal wells and cluster wells increasing speed and efficiency, saving energy and protecting the environment, large-scale factory-like operation. It was used for 145 oil wells and horizontal wells in Changqing Oilfield between 2012 and 2014, with the formulated fracturing fluid accumulated to 62.9×10⁴m³. The actual water consumption was 29.89×10⁴m³, saving 33.1×10⁴m³ of water. The recycling and utilization rate of flow-back fluid reached 97.4 percent and was recycled for 21 times at maximum. The average water-saving rate was apparently improved by reaching 52.6 percent.

Key words: recoverable, fracturing fluid, surfactant, flow-back fluid, horizontal well, staged fracturing

摘要： 酸随着长庆致密油田开发的深入,水平井大规模分段压裂成为油田开发的主导技术,但伴随着压裂改造规模的扩大,压裂用水及返排液的处理成为制约水平井改造的主要因素。针对这一困难,开发了配套的CQ-GNS压裂用稠化剂孪联非离子表面活性剂,是可回收低阻表面活性剂压裂液体系的核心成分。压裂液体系具有无残渣、低伤害、低摩阻、直接混配,尤其是返排液可直接回收后,添加相同稠化剂可循环重复利用的特点,适合水平井及丛式井提速提效、节能环保和大规模工厂化作业需求。2012—2014年在长庆油田规模化推广145口油井及水平井（1392段）,累计配制压裂液量超过62.9×10⁴m³,实际用水量29.8×10⁴m³,节约用水33.1×10⁴m³,返排液回收利用率达97.4%,最高循环利用21次,平均节水率达52.6%,节水效果明显。

关键词: 可回收, 压裂液, 表面活性剂, 返排液, 水平井, 分段压裂