喷砂射孔降破技术在超深海相碳酸盐岩的应用

Application of sandblast perforation in ultra?鄄deep marine carbonate reservoir

林永茂 何颂根 杨永华 王兴文 苏镖

（中国石化西南油气分公司石油工程技术研究院，四川 德阳 618000）

(Petroleum Engineering Technology Institute, Southwest Oil & Gas Company, SINOPEC, Deyang 618000, China)

川西气田雷口坡组海相碳酸盐岩储层具有超深、低渗、高应力等特征，面临异常高破裂压力、储层压开难度大、常规降破措施效果差的难题。针对以上难题，开展了高温高围压射孔打靶试验，明确了射孔孔眼穿深不足是降破效果有限的重要原因；引入喷砂射孔降破技术，通过工艺优化，优选20/40目石英砂为磨料，确定了喷砂参数（喷砂质量浓度100 kg/m3、喷嘴直径5 mm、喷射排量1.8~2.0 m3/min、喷砂时间25~50 min），采用了基液、冻胶、清水液体组合携砂。现场试验表明，常规降破措施无法压开的井，在喷砂射孔后，成功实现了酸压改造。喷砂射孔降破技术具有显著的降破效果，可为同类超深、高破裂压力储层改造提供借鉴。

Leikoupo reservoir in West Sichuan gas field is a marine carbonate reservoir with the characteristics of ultra?鄄deep, low permeability and high stress. With the problems of ultra?鄄high fracturing pressure and difficult formation fracturing, it is difficult for conventional fracturing pressure reduction measures. In order to solve these problems, firstly, the high temperature and high confining pressure perforation test was carried out, showing that the limited perforation depth was an important reason for the limited effect of fracturing pressure reduction. Then the sandblast perforation technology was introduced for pretreatment. By calculation and test, the abrasive of 20/40 mesh quartz sand, sand concentration of 100 kg/m3, nozzle diameter of 5 mm, pumping rate of 1.8￣2.0 m3/min, and sandblasting time of 25￣50 min were optimized. Liquid combination of linear gel, crosslinked gel and fresh water was used to carry sand. Two wells, which cannot break down the reservoir by conventional reducing fracturing pressure measures, were successfully acid fractured after sandblast perforation. This indicates that sandblast perforation can significantly reduce the fracturing pressure, and provides a reference for similar ultra?鄄deep and high fracturing pressure reservoirs.

10.6056/dkyqt201905023