固井用新型高温缓凝剂的研究与应用

针对深井、超深井长封固段大温差水泥浆柱顶部强度发展缓慢的问题,通过自由基水溶液聚合方法,研制了新型聚合物类高温缓凝剂GWH-1,并对其性能进行了评价。结果表明:GWH-1耐温可达200℃,抗盐可达饱和;通过调整GWH-1加量,能调节水泥浆的稠化时间;经130℃养护后低密度水泥浆(1.30 g/cm3)的稠化时间为386min,在30℃下养护72 h后的抗压强度大于3.5 MPa;高温水泥浆无游离液且水泥石上下密度差小于0.02 g/cm3;水泥浆综合性能良好,解决了长封固段大温差固井水泥浆顶部超缓凝难题。GWH-1在塔里木油田RP7008井等进行了应用,封固段固井质量优良。对深井长封固段提高固井质量、简化井身结构及节约钻井成本等具有重要意义。

Study and Application of New High Temperature Retarder for Well Cementing

A new high temperature polymer retarder, GWH-1, was synthesized through free radical polymerization in water solution. GWH-1 was used to deal with the slow setting of the top cement in cementing long open hole with big temperature difference. Laboratory evaluation showed that GWH-1 can stand high temperature to 200℃, and was resistant to contamination from saturated salt solution. The thickening time of the cement slurry can be adjusted by changing the concentration of GWH-1. A low density (1.30 g/cm3) cement slurry treated with GWH-1 had thickening time of 386 min, after aging at 130℃. After aging at 30℃ for 72 h, the set cement had compressive strength of 3.5 MPa. No free liquid was found for the cement slurry at high temperature, and the density difference between the top and the bottom of the set cement was less than 0.02 g/cm3. GWH-1 was successfully used in the cementing job of well RP7008 in Tarim Basin.