塔河油田桥古区块防气窜固井技术　　

Cementing technology for gas channeling prevention in Qiaogu Block of Tahe Oilfield

高元 杨广国 常连玉 高丽

GAO Yuan YANG Guangguo CHANG Lianyu GAO Li

中国石化石油工程技术研究院，北京　100101 中国石油大学胜利学院，山东东营　257061

Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China Shengli College, China University of Petroleum, Dongying 257061, China

桥古区块卡普沙良群、库姆格列木群地层稳定性差，易发生井壁垮塌掉块、缩径、卡钻等井下复杂情况，尾管封固段气层活跃，防气窜难度大。分析总结前期固井情况，考虑地层岩性特征，优选出微膨胀防气窜盐水水泥浆体系，具有API失水小于50 mL、SPN值小于3、24 h水泥石强度大于14 MPa的特点；结合应用新型分段气窜预测模型，考虑领、尾浆胶凝失重、水泥浆失水、井口加压等因素对气层压稳的影响，较真实地预测气层压稳状况，并对固井施工工艺和参数进行了优化和改进。现场应用2口井均取得了良好效果，封固段综合评定优质，满足了桥古区块固井作业要求。

The stratum of the Kapushaliang group and Kumugeliemu group is unstable, causing downhole problems such as bore hole collapse, shrinkage and bit sticking. The gas layer in liner section is active, so it is difficult to prevent gas channeling. Through analysis and summary on early cementing treatments, taking formation lithology characteristics into account, micro-swell brine cement slurry for gas channeling prevention was optimized, with API fluid loss less than 50 mL, SPN value less than 3, and compressive strength higher than 14 MPa/24 h. The new gas channeling model, which considered the impact of cement slurry static cementing strength, filter loss and wellhead loading,was used to accurately forecast gas layer stabilization. The cementing technology and parameters were optimized and improved. The technology was applied in 2 wells and achieved good results, with excellent cementing quality in isolation interval, which met the requirements of cementing in Qiaogu Block.