新型耐盐低伤害压裂稠化剂的研制及应用

文章以2-丙烯酰胺基-2-甲基丙磺酸、丙烯酰胺、甲基丙烯酰丙基三甲基氯化铵为单体，采用水溶液聚合法制备了丙烯酰胺/2-丙烯酰胺基-2-甲基丙磺酸/甲基丙烯酰丙基三甲基氯化铵三元共聚物稠化剂。研究了三元共聚物稠化剂形成的交联冻胶的耐温耐盐性、携砂性和破胶性能。结果表明，2-丙烯酰胺基-2-甲基丙磺酸：丙烯酰胺：甲基丙烯酰丙基三甲基氯化铵=2:7:1、引发剂加量为0.25%、反应温度50℃、反应时间3.5h，pH值为6～8条件下制备的三元共聚物稠化剂的具有良好的性能。以质量分数0.4%三元共聚物稠化剂为主剂的压裂液在70 000 mg/L矿化度下黏度仍大于100 mPa·s，在温度100℃、返排液条件下黏度仍为146.3 mPa·s。与羟丙基胍胶相比，三元共聚物稠化剂聚合物冻胶中支撑剂的沉降速度更小，破胶液残渣含量更少，对储层的伤害率更低。

Research and Application of New Salt-resistant and Low-damage Fracturing Thickener

Usingacrylamide(AM), 2-acrylamido-2-methyl-propanesulfon-icacid (AMPS),Methacrylamido propyl trimethyl ammonium chloride (MAPTAC)as raw materials,named asterpolymer thickener,was prepared by aqueous solution polymerization.The temperature-resistant; and salt-tolerant, sand carrying capacity and gel breaking performance of the crosslinked gel formed by terpolymer thickener were studied. The results show that, the terpolymer thickener had good performance at following polymerization reaction, the quality ratio of AMPS/AM/MAPTACwas2:7:1, the dosage of initiator was 0.25%, the reaction temperature was 50℃, the reaction time was 3.5h, and pHwas6~8. The fracturing fluidwithviscosity of 0.4% terpolymer thickener is still greater than 100 mPa·s at 70000 mg/L salinity. In the flow back condition, the viscosity of terpolymer thickener is still 146.3 mPa·s at 100℃. Compared with hydropropyl guar gum, terpolymer thickener polymer gel has lower settling speed of proppant, less residue content of gel breaker and lower damage rate to reservoir.