自愈合水泥浆体系在四川地区的应用

针对油气井开发过程中水泥环受损产生裂缝而破坏固井封隔效果，以烃触发溶胀型聚合物为自愈合乳液粒子，形成自愈合水泥浆体系。结果表明，自愈合乳液粒子的粒径在200～250 nm，其加量为10%时水泥石吸油愈合效果及机械性能较佳；8 d内水泥石裂缝愈合率达70%～100%，2 d抗压强度为16.2 MPa，弹性模量为6 GPa；渗流实验结果表明，水泥石出现大于0.1 mm裂缝时，柴油气流速由9 g/min降至6 g/min，小于0.1 mm的裂缝时柴油流速由6 g/min可降低为0。说明自愈合水泥石一旦产生损伤，裂缝中渗入的油气分子使自愈合乳液粒子自发膨胀黏连并逐步修复闭合裂隙，裂缝越小自愈合效果越好，实现了水泥石自愈合修复功能。现场应用表明，该水泥浆体系固井质量优质率达到 88.9%，固井及压裂后技术套管均不带压，显示出良好的应用效果。 

Application of Autonomous Healing Cement Slurry System in Sichuan

Aiming at the problem of damage effect of cementing isolation caused by formation of crack in cement sheath during the development of oil and gas wells, the hydrocarbon-triggered swelling polymer was used as self-healing particles to form an autonomous healing cement slurry system. The experimental results show that when the self-healing particle size is 200-250 nm and the amount is about 10%, the cement stone has better oil absorption healing effect and mechanical properties: the cement stone crack healing rate is 70%-100% within 8 days, and the 2 d compressive strength is 16.2 MPa, elastic modulus 6 GPa. Seepage experiments show that the flow rate of oil and gas in cracks of cement stone larger than 0.1 mm is reduced from 9 g/min to 6 g/min, and the flow rate of cracks smaller than 0.1 mm can be reduced from 6 g/min to 0. This shows that once the autonomous healing cement is damaged, the oil and gas molecules infiltrated into the crack and the self-healing particles spontaneously expand and adhere, then the cracks are gradually repaired. It can realize that the cement has self-healing function. The smaller the crack, the better the self-healing effect. The field application in Sichuan shows that the cementing quality of the autonomous healing cement system reached 88.9%, and the technical casing pressures after cementing and fracturing were not appeared, showing good application effects.