黏弹性固井封隔材料的室内研究

Laboratory Study of Viscoelastic Isolation Additive for Use in Oil Well Cementing

固井材料作为层间封隔和保护套管的主要载体,一直是固井领域研究的主要方向。利用聚合物特有的黏弹属性制备了新型固井封隔材料——DQV,将其与油井水泥配合使用就相当于给环空加上了高效、柔韧的"密封圈"。与G级原浆相比,引入DQV后环空抗窜压力可提高10倍、综合渗透率降低2个数量级,改善效果显著。同时,该材料稠化时间可调、流动度为25 cm、游离液为0、施工性能良好。在此基础上,对其现场应用方案进行了研究,对环空抗窜封隔能力的提高及固井质量的改善起到有益的借鉴作用。

A new cementing additive,DQV,was prepared making the use of polymer's viscoelasticity.DQV is an additive used in cement slurry for better isolating formation and casing string.When mixed with cementing slurry,the mixture can render the annular space very good sealing,both efficient and flexible.Cement slurry treated with DQX had anti-migration capacity that was ten times of the original class G cement slurry,and the overall permeability of the set cement was reduced by two orders of magnitude.Meanwhile,the thickening time of the cement slurry was adjustable.The mobility and free water of the cement slurry were 25 cm and0,respectively.Field application program for the cementing job using DQV was also studied for better anti-migration and isolation capacities of the cement slurry.