低温浅层稠油井固井水泥浆体系研究及应用

套保稠油区块油藏埋深浅，油层温度低、孔隙度和渗透性高、碱敏性强、岩性疏松、底水丰富，且存在漏层。现用水泥浆体系存在滤失量不易控制、浆体收缩大、界面胶结质量较差或不理想等问题。据此设计了速凝早强低滤失膨胀水泥浆体系的配方，井在套保油田现场试验了3口井。F17C膨胀降滤失剂的优良性能来自于多膨胀源的综合作用．其膨胀驱动力源于膨胀性成分反应产物的结晶生长压。优异的降滤失效果得益于对滤饼渗透能力的控制；sK速凝材料的作用来源于高活性晶种诱导、加速水泥水化作用的贡献。现场应用结果表明：以F17C低滤失膨胀剂为主．辅以SK速凝早强材料的水泥浆体系．具有速凝、早强、低滤失、微膨胀和零析水的特性．可显著提高浅层稠油井的固井质量。

Cementing composition and its application in shallow reservoir at BHST

Low temperature, high porosity and permeability, strong alkali sensitivity, loose limestone, circulation loss and basal water abundance are the formation characteristics of shallow reservoir in Taobao viscous oil area. One of the major problems in cementing at low borehole static temperature (BHST) is how to design the cement slurry. A controllable fluid-loss expansive material with high compressive strength as well as accelerated set time for cement has been designed to remedy the shortages of conventional cement slurry such as slurry body shrinkage and poor cementing quality. The experimental findings indicated that the slurry with F17C multifunction expansive material and SK quick set materials shown not only significant expansion both in plastic and set conditions but also lower filtration, accelerated set time and rapid strength growth. The composition was used in three wells and showed excellent cementing quality in the first and the second bond interfaces. It proved to be a successful material for improving the cementing quality in shallow wells at low BHST.