胶凝酸与交联酸一体化耐高温缓速酸研究

胶凝酸和交联酸是高温碳酸盐岩酸压常用的缓速酸体系，该体系存在耐温能力不足、配伍差等问题，同时现场交联酸和胶凝酸为不同酸液体系，存在配制使用流程繁琐的问题。为解决上述问题，优化形成了一体化酸液体系，交联酸基液可作为胶凝酸使用，加入交联剂作为交联酸使用。交联酸配方为:20%盐酸+1%稠化剂SRAP-2+2.5%高温缓蚀剂主剂SRAI-1+0.5%增效剂+1%酸压用铁离子稳定剂SRAF-1+1%酸压用破乳剂SRAD-1+1%交联剂SRAC-2A和延迟交联剂SRAC-2B（2:12）。胶凝酸在160℃、170 s-1下，恒温剪切120 min后黏度为20 mPa·s。交联酸体系交联时间为93 s，具有良好的延迟交联特性；在160℃、170 s-1下恒温剪切90 min后黏度为55 mPa·s，一体化酸液体系室温可放置10 d以上，在140℃动态腐蚀速率为46.1021 g/（m2·h）。研究结果表明，该体系可满足高温储层对缓速酸的要求，实现酸液体系一体化，方便现场施工，具有较好的发展前景。 

Study on the Integration of Gelled Acid and Crosslinked Acid to Form High Temperature Retarded Acid

Gelled acid and crosslinked acid are common retarded acids used in acidizing high temperature carbonate rock reservoirs. As different acids, gelled acid and crosslinked acid both have poor high temperature tolerance, poor compatibility with each other and complex formulating and working procedures. To resolve these problems, a retarded acid has been formulated through integration of gelled acid and crosslinked acid. The base fluid of the crosslinked acid can be used as a gelled acid which can be turned into crosslinked acid by adding crosslinking agents. The composition of the crosslinked acid is:20%HCl+1%SRAP-2 (thickening agent)+ 2.5%SRAI-1 (high temperature primary corrosion inhibitor)+0.5% extender+1%SRAF-1(ferric ion stabilizer for acid fracturing)+1% SRAD-1 (demulsifier for acid fracturing)+1% SRAC-2A (crosslinking agent) and SRAC-2B (delayed crosslinking agent) (SRAC-2A:SRAC-2B=2:12). After shearing at 160℃ and 170 s-1 for 120 min, the viscosity of the gelled acid was 20 mPa·s. Time for the crosslinking of the crosslinked acid was 93 s, indicating that the crosslinked acid had excellent delayed crosslinking property. After shearing at 160℃ and 170 s-1 for 90 min, the viscosity of the crosslinked acid was 55 mPa·s. This integrated acid can stand at room temperatures for more than 10 d, and the dynamic rate of corrosion at 140℃ was 46.1021 g/(m2·h). Research work shows that this integrated acid is able to satisfy the needs for retarded acid in acid fracturing high temperature reservoirs. Integration of gelled acid and crosslinked acid simplifies field operation, and should have good application prospects.