交联聚乙烯醇的防窜机理及应用

介绍了一种以交联聚乙烯醇为基础的防窜油井水泥降失水剂,通过在水泥和地层界面间形成一层具有一定韧性的聚合物薄膜滤饼,产生对流体侵入的附加阻力p附,使得P地〈P静＋P阻＋P附，来达到防止地层流体侵入的目的。水泥浆的失水量可以控制在60ml。以下，稠化时间容易调节，游离液较小，水泥浆总体性能良好，24h水泥石抗压强度较高，能够满足一般油气井固井的要求。列举了其水泥浆的综合性能以及在陆地油田和渤海油田应用的实例。

Anti-Channeling Mechanism and Application of Croslinked Poly Vinyl Alcohol

This paper discusses a filtration control agent for cement slurries.The crosslinked poly vinyl alcohol in the filtration control agent can form a polymer film on the interface between cement sheath and formations,thereby generating an additional resistance,to the flow of fluid into the formations.Using this filtration control agent,the water loss of cement slurries can be reduced to less than 60 mL,and the thickening time of slurries is easily controlled.The amount of free fluid is also minimized.Moreover,the 24 h compressive strength of set cement is not affected by this filtration control agent.