吸附型缓速酸体系的开发与应用

针对目前常规酸液体系反应速度快，有效作用距离短，刻蚀效果差等问题，研究了一种吸附型缓速酸体系。该体系通过缓速剂中阳离子疏水基团吸附在岩石表面，形成保护膜将酸液中H+隔离，延缓酸岩反应时间，提高酸蚀裂缝长度及非均匀刻蚀程度。进行了酸液、添加剂加量优化，得到缓速酸体系配方。性能评价结果表明，该体系缓速率为91.2%，缓蚀率为99.6%，缓速酸与岩石反应形成了较明显的沟槽且导流能力随闭合压力升高降幅较小，缓速效果明显。该体系在苏里格地区得以成功应用，单井产气量是相邻井产量的5倍左右，改造效果显著。 

Development and Application of an Adsorptive Retarded Acid

Conventional acids for acidizing job have some disadvantages such as fast reaction, short effective functioning distance and poor erosion etc. To address these problems encountered in acidizing with conventional acids, an adsorptive retarded acid was developed, in which the hydrophobic cationic groups of the retarder are able to adsorb on the surfaces of formation rocks, forming a protective membrane to shut off the contact of H+ and the surfaces of the rocks, thereby retarding the reaction between acid and rocks, and increasing the length of acid-corroded fractures and the inhomogeneity of acid corrosion. A retarded acid formulation was developed based on the optimization acid concentration and the concentration of other additives. Evaluation of the performance of the retarded acid showed that the acid was retarded by 91.2% and the rate of corrosion was retarded by 99.6%. Reaction of the retarded acid and rocks produced clear ditches and trenches, and the flow conductivity of the ditches and trenches drops at a low magnitude as enclosure pressure is increasing, fully proving the retarding capacity of the retarded acid. This retarded acid has been successfully used in Sulige gas field, the daily gas production rate of an individual well was 5 times that of gas wells nearby.