吉林油田浅层气井固井防窜水泥浆体系

Research on Anti-channeling Cement Slurry in Shallow Gas Wells of Jilin Oil Field

气窜严重是吉林油田浅层气井固井存在的一大技术难题,为此开发了浅层气井固井防窜水泥浆,该水泥浆具有流动性好、失水量低、稠化时间合适、过渡时间短和早期强度高等优点。开发的固井水泥浆,领浆中加入1.4%降失水剂JLS和3%晶体膨胀剂KW-2,水泥浆失水量为16 mL,稠化时间为130 min,浆体SPN值为1.07,24 h水泥石的抗压强度和线膨胀率分别为20.5 MPa和0.011%;尾浆中加入1.4%JLS、3%KW-2和2%速凝早强剂ZQJ,水泥浆失水量为14 mL,稠化时间为108 min,浆体SPN值为0.90,24 h水泥石的抗压强度和线膨胀率分别为23.7 MPa和0.003%。现场34口气井的应用实践证明,该防气窜水泥浆适合浅层气井的固井开发,固井合格率为100%,优质率为88.2%。

The gas channeling is a major technical problem existing in shallow gas wells of Jilin oil field.To improve the cementing quality of shallow gas wells,an anti-channeling cement slurry system is developed.Experiment results show that the cement slurry has many advantages of good rheology,low filtration,fitting thickening time,short transition time and high early strength.For the initial cement slurry which contains 1.4% fluid loss additive JLS and 3.0% crystalline expansive agent KW-2,the fluid loss is 16 mL,thickening time is 130 min,the value of SPN is 1.07,and the compressive strength and linear expansion rate of 1 day aged set cement are 20.5 MPa and 0.011%.For the tail slurry with 1.4% fluid loss additive JLS,3.0% expansive agent KW-2 and 2% accelerating setting and high early strength agent ZQJ,the fluid loss is 14mL,thickening time is 108 min,the value of SPN is 0.90,the compressive strength and linear expansion rate of 1d aged set cement are 23.7 MPa and 0.003%.The applications in 34 gas wells are successful,and the percent of 'up to standard' rate of cementing is 100%,of which 88.2% is of high quality.