碳酸盐岩储层深度酸压用固体颗粒酸的研制

Development of Solid Granular Acid for the Deep Acid-Fracturing of Carbonate Reservoirs

在采用常规酸液对高温碳酸盐岩储层进行酸化改造时,存在酸岩反应速率快、有效作用距离短和难以实现深部酸化的难题,为此,以磺基酸为心材,以有机磺酸和乙基纤维素复合材料为壁材,采用喷雾干燥工艺固化造粒,研制了一种新型固体颗粒酸。试验评价表明,该固体酸在80~90℃温度下可逐步释放出酸液,120℃下的完全释放时间为25 min,有效酸质量分数达10.3%以上,反应速率低,可由液体介质携带到裂缝深处。塔河油田THX井应用固体颗粒酸酸化后,日产油量大幅提高。研究表明,固体颗粒酸能有效沟通远端储层,为碳酸盐岩储层高效开发提供了一种新的技术手段。

Due to acidizing problems present in high-temperature carbonate reservoirs from conventional acids,such as rapid acid-rock reaction,short effective action distance and difficulty in achieving deep acidizing,a new type of solid granular acid has been developed.The solid acid was prepared by taking sulfonic acid as the core material and using organic sulfonic acid/ethyl cellulose composite as capsule materials,and it could be solidified and granulated by adopting a spray drying process.The capsule material can be dissolved gradually and then an acid solution can be released at a certain temperature,so as to increase the action distance of acid.Experimental evaluation showed that the developed solid acid could release an acid solution gradually at a temperature range of 80 to 90℃,the complete release time at 120℃ was 25 min,and the effective acid concentration was up to 10.3%.Due to the low reaction rate,it can be carried into the deep fractures by liquid media.Field testing of solid granular acid has been conducted in the well THX of the Tahe Oilfield,and the daily oil production capacity was greatly improved.Studies indicated that the solid granular acid could effectively communicate with distal reservoirs,and provide a new technical means for the efficient development of carbonate reservoirs.