研究了一种低密度(1.30 g/cm3)可固化防漏工作液,用于解决低压易漏失井段在固井时,因地层承压能力低、易漏失、窜槽,导致固井质量不高的问题.通过在优质的隔离液中加入一种具有固化性能的材料(2.60~2.90 g/cm3)替代常规的加重剂,配制一种低密度可固化工作液.该工作液能有效平衡地层压力并在环空中固化,从而对易漏地层起到防漏效果、提高固井质量.重点分析了该体系的固化后试样强度及水化机理,研究发现:工作液固化强度发展的实质是OH-对固化剂玻璃体结构的破坏;通过对配方的调节能实现从30~90℃固化试样都具备一定的抗压强度.该体系的研发对于防漏工作液的设计提供了一种新的思路,同时还可以运用于钻井工程中堵漏,提高地层的承压能力.%While cementing in the low pressure and easy to leak hole section, low formation bearing pressure、leakage and channeling often lead to low cementing quality. So a low density (1.30 g/cm3) working fluid which can be solidifiable and prevent leakage was studied to solve the problem. The working fluid was made form the high quality spacer fluid in which a kind of curing properties of the material (2.60~2.90 g/cm3)replacing weighting material was added. The working fluid can effectively balance formation pressure and cure in annulus, thus preventing leakage and improving cementing quality. The strength of samples after curing and hydration mechanism of the working fluid were mainly analyzed in the paper. The results showed that the structure of the curing strength development is that hydroxyl ions damaged the vitreous body structure of the curing agent. Through the adjustment of the formula, curing test specimens from 30~90 ℃ had a certain compressive strength. The research and development of the working fluid system provided a new way for the design of the leak protection working fluid. The working fluid system can also be applied to sealing in drilling engineering to increasing the formation bearing pressure.
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