高温交联酸用稠化剂合成及性能评价

The Synthesis and Evaluation of Thickeners for Crosslinked Acid with High Temperature Resistance

利用丙烯酰胺(AM)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)作为原料,进行水溶液聚合,采用低温复合引发体系制备高温交联酸用稠化剂P(AM-co-AMPS),通过单因素分析法确定最佳反应条件;并对其纯化样品进行红外表征,室内性能评价。结果表明,该稠化剂酸溶性好,基液黏度随稠化剂加量增加而增大,配方:20%HCl+0.8%稠化剂+5%BZ酸化缓蚀剂+2%BZ措施用破乳助排剂+2%BZ酸化用铁离子稳定剂+0.3%BZ交联延迟剂。加入交联液(交联剂/交联延迟剂=1,交联比∶100∶0.8),90 s后能形成可挑挂冻胶,180℃,170 s^(-1)剪切速率下,剪切100 min,黏度保持在56 mPa·s左右。加入破胶剂后,在90℃加热1 h,破胶黏度为10 m Pa·s,利于酸液返排,可满足高温储层对交联酸的要求,具有较好的发展前景。

A kind of thickener P（ AM-co-AMPS） was prepared by aqueous solution polymerization,using acrylamide（ AM） and 2-acrylamide-2-methylpropanesulfonic acid（ AMPS） as the monomers and employing a novel initiator system. The optimum conditions were determined by the single factor analytic approach. The product was characterized by IR and proved to be the target product. Lab test result shows that the thickener has good acid solubility. When the formulation was as follow,20% HCl ＋ 0. 8% thickener ＋ 5% corrosion inhibitor ＋ 2% demulsify-cleanup additive ＋ 2% ferric ion stabilizer ＋ 0. 3% delayed crosslinker,the crosslinked fluid（ crosslinking agent / delayed crosslinker = 1,crosslinking ratio is 100 /0. 8） can crosslink the thickener effectively to form crosslinked acid and the crosslinking time was 90 s. After sheared at 180 ℃ and the shearing rate of 170 s- 1 for 100 min,the viscosity of the system could maintain up to 56 m Pa·s. The viscosity of breaked gel dropped to 10 mPa·s,after added gel breaker and kept under 90 ℃ for 1 h. It can satisfy the requirement of acidizing of high temperature reservoirs. So we believe that the crosslinked acid system could meet the requirements with a good respect of application.