油醇系浓缩缔合聚合物压裂液增稠剂的制备与应用

Preparation and Application of Concentrated Oleic Alcohol Association Polymer Thickening Agent Used in Fracturing Fluids

针对目前压裂液干粉增稠剂连续配注工艺技术,存在劳动强度大、粉尘大、混合不均匀、溶解时间长、易形成粉粒和产生局部冻胶结块等问题,研究开发了一种由液体石蜡、甲醇、疏水缔合聚合物增稠剂、分散剂配制而成的稳定性、流动性均良好的油醇系浓缩缔合非交联压裂液增稠剂。性能测试结果表明,该油醇系浓缩缔合非交联压裂液增稠剂配制的压裂液水化时间仅为2 min,溶解过程中无"鱼眼",可实现现场快速配制,缔合非交联压裂液具有良好的耐温抗剪切性,当增稠剂有效质量分数为0.65%时,在150℃,170 s^(-1)下恒温剪切2 h,黏度保留值为103 mPa·s。此外,缔合非交联压裂液还具有携砂性佳、易破胶返排、低摩阻(降阻率为63.15%)、低残渣(小于80 mg/L)、低滤失、低伤害(动态滤失渗透率损害率为30%)的特点,较瓜胶压裂液性能更优,是一种性能好的清洁型压裂液。该缔合非交联压裂液目前在胜利A区8口井的应用,取得了良好的应用效果。

Several problems have long existed in continuous preparation and injection of fracturing fluid with dry thickening agents. These problems include high labor intensity, dusting, non-homogeneity of the fracturing fluid （such as generation of solid particles and gel conglomerates of dry thickening agents when dissolving in water）, and long dissolution time of thickening agents etc. A new concentrated oleic alcohol association polymer thickening agent was recently developed to solve these problems. The new thickening agent is made of liquid paraffin, methanol, hydrophobic association polymers thickening agents and dispersant, and has good stability and mobility. In laboratory testing, this new thickening agent, a non-crosslinking polymer, dissolved completely in water in only 2 rain, and no fisheyes have been found in the solution, making it possible to prepare fracturing fluid fast at well site. A fracturing fluid treated with 0.65% （mass fraction） of the thickening agent has a retained viscosity of 103 mPa＇s after shearing at 150 ℃ and 170 s^-1 for 2 h. Compared with guar gum fracturing fluids, fracturing fluid prepared with the new thickening agent has better sand carrying capacity, lower friction coefficient （rate of friction reduction is 63.15%）, less residue （less than 80 mg/L）, less filter loss and lower formation damage （in dynamic filtration test, permeability impairment was 30%）. Fracturing fluids treated with this new thickening agent have been successfully used in 8 wells in Block A, Shengli oilfield.