增韧水泥浆用于修补长庆油田采油三厂套损井

Toughened Cement Slurry for Repairing Casing Damage in Oil Wells of the Third Changqing Production Factory

为修补破损的水泥环和套管,研制了以纤维材料和颗粒剂为主要材料的两种复合增韧剂CSDL-1和CSDL-2,给出了配方。将增韧剂掺入G级油井水泥,按水灰比0.44配制成两种增韧水泥浆,在80℃下其初凝时间分别为11-12小时和8-9小时,终凝时间分别为18小时和14小时,均可适当调整,在淡水和盐水中,在室温自由养护、60℃高压养护,三轴应力养护后的抗压强度均大于24 MPa,其胶结强度高,随温度升高（20-100℃）边疆增大。断裂面电镜照片表明纤维材料减缓了裂纹的扩展。介绍了用该增韧水泥浆成功修补两口套损井的情况。

For repairing damaged cement sheath and casing, two toughening compositions with fibrous and particulated materials as main ingredients, notated as CSDL-1 and CSDL-2,were screened and their formulas were presented. These compositions were mixed with oilweU cement of grade G and CSDL-1 and CSDL-2 toughened cement slurries were prepared at water-cement ratio = 0. 44. These two cement slurries had an initial setting time of 11--12 and 8--9 his and a final setting time of 18 and 14 hrs,respecfively,with the two characteristic time being adjnstible to some extent. The compression strength of the set toughened cements was no less than 24 MPa no matter the cure was conducted at room temperature without pressure applied, at high temperature （60℃） and high pressure or under triaxial stress. Their bonding strength was high and increased with raising temperature from 20℃ to 100℃. The SEM photos of fractured set cement section indicated the hidering of fracture propagation by the fibrous material. These toughness enhancing cement slurries were successfully used in repairing jobs in two oil wells with damaged easing.