适用于冬季施工的清洁压裂液体系评价及应用

Evaluation and Application of Clean Fracturing Fluid System Suitable for Winter Operation

通过利用捷贝通耐温抗盐清洁压裂液体系为基础配方,根据新疆油田冬季施工要求,经过大量的室内评价开发出一套适用于冬季施工的清洁压裂液体系,并进行了现场应用。通过室内评价及现场应用结果表明,该体系具有以下优点:基液黏度低,可实现支撑剂在基液中的均匀分布;低温下正常交联,低排量下支撑剂不会迅速沉降;防冻性能好,压裂液在-15℃下保持流动状态;与储层配伍性好,不会出现压裂返胶现象;携砂性能好,常温携砂,36 h不沉降;高温下耐剪切性能好,在100℃下剪切60 min尾黏大于100 mPa·s;冻胶呈中性,不会对管道、设备产生腐蚀;破胶液表、界面张力低,有利于破胶液返排;抗二价铁离子效果好。

A set of clean fracturing fluid system suitable for winter operation in Xinjiang was developed through series of laboratory experiments based on Gepetto’s temperature-resistant and salt-resistant cleaning fracturing fluid system.And it was applied in the oilfield.The results of laboratory evaluation experiments and field application showed that the system has the following advantages:the viscosity of the base liquid is low,and the uniform distribution of the proppant in the base liquid can be achieved;Normal cross-linking reaction can occur at low temperature,the proppant does not settle quickly at low injection rate;The anti-freeze performance is good,and the fracturing fluid keeps flowing at-15°C;It has good compatibility with the reservoir and will not cause fracturing fluid to re-gel;it has good sand carrying performance,no sand settlement occur in 36 h at normal temperature;The shear resistance is good at high temperature,and the tail viscosity is more than 100 mPa·s after shearing at 100℃for 60 min;The gel is neutral and will not cause pipes and equipment to corrode;The broken-glue liquid has low surface and interfacial tensions and is beneficial to the backflow;The effect of resisting divalent iron ions is good.