一种添加环氧树脂乳液的优质固井水泥浆

High-quality cementing slurry with epoxy resin emulsion

较之于常规聚合物乳液,环氧树脂乳液固化后机械强度、韧性和耐腐蚀性良好,具有显著改善固井水泥浆性能的潜力,是未来固井水泥浆技术的主要发展方向之一。为此,通过防气窜性能评价、力学性能测试、扫描电子显微镜(SEM)微观分析等实验测试技术手段,系统分析了不同环氧树脂乳液掺量对水泥浆性能的影响规律,研发了一种环氧树脂水泥浆乳液并开展了现场应用。研究结果表明:①环氧树脂乳液水泥浆静胶凝强度发展过渡时间较常规水泥缩短65.6%,在气侵危险时间内的水泥浆自然失重速率降低63.3%;②环氧树脂水泥石48 h抗压强度较常规水泥石增加了2.1倍,弹性模量降低了53.7%;③随着环氧树脂乳液加量的增加,环氧树脂固化后均匀分布于水泥石内部形成致密的三维网状结构,提高了水泥石的力学性能;④现场应用3口井的固井质量良好,均未出现环空带压等问题,水泥环层间封隔质量良好。结论认为,环氧树脂乳液的加入能有效解决固井水泥浆防气窜性能差、水泥石脆性大的问题,能有效防止环空异常带压的问题,对于延长油气井开采寿命具有重要意义。

Compared with conventional polymer emulsions,epoxy resin emulsion is better in mechanical strength,toughness and corrosion resistance after solidification and has the potential of improving the properties of cementing slurry significantly,so it is one of the main development directions of cementing slurry technologies in the future.In this paper,the influence of different epoxy resin emulsion dosages on the properties of cement slurry is systematically investigated by means of anti-gas channeling performance evaluation,mechanical property testing and SEM microscopic analysis.In addition,epoxy resin emulsion is developed and field application is carried out.And the following research results are obtained.First,compared with conventional cement,the transition time of the development of static gel strength of epoxy resin emulsion slurry is 65.6%shorter and the natural weight loss rate of cement slurry in the risk time of gas invasion is 63.3%lower.Second,compared with conventional set cement,the 48 h compressive strength of epoxy resin set cement is 2.1 times higher and the elastic modulus is 53.7%lower.Third,with the increase of resin dosage,the solidified resin is evenly distributed inside the set cement to form a dense three-dimensional network structure,which improves the mechanical properties of set cement.Fourth,in the three wells where the high-quality cementing slurry with epoxy resin emulsion is applied,cementing quality is high,sustained casing pressure does not occur and interlayer isolation of cement sheath is good.In conclusion,epoxy resin emulsion can effectively solve the poor anti-gas channeling performance of cementing slurry and the high brittleness of set cement and prevent sustained casing pressure,therefore,it is of important significance in extending the production life of oil and gas wells.