交联酸携砂压裂工艺在碳酸盐岩储层的应用

近年来，针对碳酸盐岩的储层改造，中外已形成了以深度酸压为主体的各种酸压技术，同时还尝试了加砂压裂改造。在分析酸压和加砂压裂不足的基础上，针对长庆气田下古生界碳酸盐岩储层特点开发了交联酸携砂压裂工艺，交联酸压裂液具有黏度高、滤失低、摩阻低、易泵送、酸岩反应速度慢、造缝效率高、返排容易、流变性好、能携砂等一系列优点，从而实现酸液体系深穿透、提高酸蚀裂缝导流能力、延长压后有效期、提高单井产能的目的。从2006年以来先后运用该技术在靖边气田对碳酸盐岩储层进行交联酸携砂压工艺改造试验，与邻近井的其他施工工艺增产效果相比有一定的优越性。

Application of cross-linked acid-carrying sand fracturing technology to carbonate reservoirs

In recent years, in view of transformation of carbonate reservoirs, a variety of acid fracturing technologies taking deep acid fracturing as the focal have been developed both at home and abroad. At the same time, sand fracturing is tested by trial. Based on analyzing the shortcomings of acid fracturing and sand fracturing, the cross-linked acid-carrying fracturing technology is developed, according to the characteristics of the Lower Paleozoic carbonate reservoir in Changqing gas field. Cross-linked acid fracturing fluid features in high viscosity, low filtration, low friction, convenient pump delivery, slow acid-rock reaction, high efficiency in seam building, easy flowback, good rheological property, and good sand-carrying capability. So the target to achieve deep penetration of acid system, improve conductivity of etching cracks, extend the validity period after fracturing, and improve the single well capacity can be fulfilled. The technology has been used for the cross-linked acid-carrying sand fracturing test of carbonate reservoirs in Jingbian gas field successively since 2006. Statistics of 23 wells show that the success rate and efficiency of using the technology reach 100%. In the carbonate reservoir with similar physical property and gas bearing property, the average absolute open flow (AOF) reaches 13.791×10~4 m~3/d after using the technology. While the average AOF of eight wells is only 9.745×10~4 m~3/d after hydraulic fracturing. Te production is therefore increased a lot by using the technology.