高温深部碳酸盐岩储层酸化压裂用交联酸体系制备及性能

Preparation and Characteristic of Cross-linked Acid for High-temperature Acid Fracturing System of Deep Carbonate Reservoirs

王增宝 付敏杰 宋 奇 汪 淼 赵修太 王彦玲

WANG Zengbao FU Minjie SONG Qi WANG Miao ZHAO Xiutai WANG Yanling

常规酸液体系不适用于高温（＞140℃）深部碳酸盐岩储层酸化压裂改造。为了获得耐温性能优良的酸液体系， 按质量比 12∶15∶30∶15∶0.125将氧氯化锆、 水、 异丙醇、 乳酸和木糖醇混合后在 50数 55℃条件下反应 3数 4h 合成了耐温有机锆交联剂 ECA-1， 优选出了酸化压裂用稠化剂 EVA-180， 确定了交联酸体系最佳配方： 20%HCl+0.8%～ 1.2% 稠化剂 EVA-180+3.0%～ 5.0% 交联剂 ECA-1+0.03%破胶剂 EBA， 研究了该交联酸体系的高温流变性能、 缓速性能、 破胶性能及体系微观结构。结果表明， 该交联酸体系的耐温抗剪切性能良好， 成胶强度＞0.06 MPa， 140℃、 170 s-1条件下剪切 1 h后的黏度在 100 mPa·s左右； 与大理石反应 10 h后溶蚀率为 60%， 具有良好的缓速性能， 可实现深部酸化。此外， 该交联酸体系破胶彻底， 无残渣， 破胶液黏度为 3 mPa·s， 易于返排。微观结构分析表明， 有机锆的加入使稠化酸形成了具有错综致密网状结构的交联酸， 从而提高了交联酸体系的耐温抗剪切性能和缓速性能。图8表3参17

With the needs of the development of deep and ultra-deep carbonate reservoirs，the conventional acid liquid system couldn’ t meet the demands of acid fracturing in deep carbonate reservoirs with high temperature. In order to obtain the acid liquid system with good anti-temperature performance，an anti-temperature cross-linking agent of organic zirconium ECA-1 was synthesized when zirconium oxychloride， water， isopropyl alcohol， lactic acid and xylitol was mixed at the mass ratio of 12∶15∶30∶15∶0.125 and reacted for 3—4 h at 50—55℃ . Meanwhile，EVA-180 was selected as the thickening agents used under high temperature. The formula of the cross-linked acid（CLA）system was finally settled as： 20%HCl+0.8%—1.2% EVA-180+3.0%—5.0% ECA-1+0.03%EBA， the gelling strength of the CLA system was higher than 0.06 MPa. The high temperature rheological， retarding and viscosity-breaking property of the system were evaluated，and micro-structure was also studied by electronic microscope scanning. The results showed the viscosity of the CLA system was about 100 mPa·s after sheared for 1 h at the temperature of 140℃ and at the shear rate of 170 s-1， which indicated the CLA system had good temperature and shear tolerance. The CLA system had good retarding property， the dissolution rate of marble was of 60% after dissolution reaction for 10 h， which ensured that the CLA system could flow into the deep layer. In addition， the system could break thoroughly， the viscosity of the breaking fluid was merely 3 mPa·s， which guaranteed the CLA system could flow-back easily. As a result， the CLA system could perfectly meet the basic needs of acid fracturing under high temperature. Microstructure analysis showed that the cross-linking reaction occurred after adding the organic zirconium into the gelled acid， and a complex and dense mesh structure of the CLA system was formed， which improved the shear resistance of heat-resistant and retarding property of the CLA system.

10.19346/j.cnki.1000-4092.2016.04.007