超深碳酸盐岩裸眼分段完井可溶球研究与应用

Research and Application of Soluble Balls for Segregated Open Hole Completion in Ultra-Deep Carbonate Reservoirs

针对顺北油田5号条带超深碳酸盐岩储层裸眼分段完井工艺特点,研究设计了一种可控溶解的压裂球,主要用以解决“高耐酸腐蚀性、高速溶解特性、耐高压性能”等3个问题。可溶球采用“基体+涂层”结构,基体材料采用镁铝合金,涂层优选改性聚四氟乙烯+酚醛树脂纳米材料,并使用有机涂层对镁铝合金进行表面处理。对新研制的可溶球分别进行了承压数值仿真分析、耐酸承压测试和高温溶解测试,最后在顺北4-13H井进行了现场应用。研究结果表明:新研制的可溶球能够承受高温160℃、高压70 MPa、耐酸且能高速溶解,平均溶解速率为7.19 g/h,完全溶解只需12 h左右,实现了压裂时承压、生产时快速溶解不堵塞通道的双重要求,能有效提高可溶球在顺北区块裸眼分段完井工艺中的适用性和有效性,满足现场使用需求。研究结果可为油田现场水平井分段完井工艺提供参考。

According to the technological characteristics of segregated open hole completion in ultra-deep carbonate reservoir of No.5 belt in Shunbei oilfield,a controllable soluble fracturing ball was studied and designed to solve 3 problems such as high acid corrosion resistance,high-speed solubility and high-pressure resistance.A “base + coating” structure was adopted for the soluble ball: magnalium was used as base material,a modified teflon + phenolic resin nanophase material was selected for coating,and an organic coating was used to conduct surface treatment on magnalium.A pressure bearing numerical simulation analysis,an acid resistance pressure bearing test and a high-temperature dissolution test were conducted on the newly developed soluble balls respectively,and finally,they were applied in Well Shunbei 4-13H.The research results show that the newly developed soluble ball can withstand high temperature of 160 ℃,high pressure of 70 MPa,is resistant to acid,and can dissolve at high speed;the average dissolution rate is 7.19 g/h,and complete dissolution only takes about 12 h;it meets the dual requirements of pressure bearing during fracturing and fast dissolution during production without blocking the channel;it can effectively improve the applicability and effectiveness of soluble balls in segregated open hole completion process in the Shunbei block,and meet the needs of field application.The research results provide reference for the segregated completion technology of horizontal wells in the oilfield.