新型膨胀剂在胶乳水泥浆体系中的应用

油井水泥固有的收缩特性是造成水泥环-地层、水泥环-套管间胶结质量不理想而诱发气窜的原因之一。在分析油井水泥膨胀剂作用机理的基础上,通过试验研制出了新型膨胀剂PZ-3S,该膨胀剂能有效降低水泥浆的凝结收缩率和提高水泥石的界面胶结强度,改善固井水泥环与套管和地层胶结界面的胶结质量,防止界面窜流,且有助于水泥石抗压强度的提高。同时,验证了该膨胀剂与胶乳水泥浆体系具有良好的相容性,对胶乳水泥浆体系的综合性能(如失水、稠化时间、自由水、流变性等)无不良影响。现场应用表明,膨胀剂PZ-3S加入胶乳水泥浆体系后能有效提高水泥石的抗压强度和胶结强度,能减少微环隙产生的可能性和提高胶孔水泥浆体系的防窜性能。

The Development of New Style Expansion Agent and Its Applications in Latex Cement System

The well cement shrinkage is the main reason to cause the poor quality between cement-sheath and formation,cement-sheath and casing,which resulting in gas migration at the agglutinate interface.A new style swelling agent PZ-3S was developed on the basis of analysis of the theory of swelling agent.It can reduce the coagulation shrinkage and increase the interfacial cementing strength,improving the cementing quality between cement-sheath and formation,cement-sheath and casing to prevent gas migration,which helps the improvement of the slurry compression strength.Furthermore,the expansion agent is fit for latex cement systems and does not impact the comprehensive performance(such as water loss,thickening time,mobile water,flow properties etc.).The field application indicates that by adding swelling agent PZ-3S to the latex cement systems increased the cement compression strength and consolidation strength,reduced the occurrence of minor gap and prevented of gas migration.