泡沫分数对泡沫水泥性能的影响规律分析

Effect of Gas Volume Fraction in Foam on Performance of Foam Cement Slurry

泡沫水泥的性能主要取决于泡沫体积分数。通过水泥浆发泡实验,制备了具有良好沉降稳定性的泡沫水泥,深入系统分析了泡沫体积分数的变化对泡沫水泥的性能影响。研究结果表明,随着泡沫体积分数的增大,泡沫水泥浆变得黏稠,失水量降低;同时,泡沫水泥石抗压强度基本成线性降低,气测渗透率升高,弹塑性能增强。泡沫体积分数控制在30%左右,泡沫水泥石具有较好的抗压强度和弹塑性能,同时满足气层的有效封固要求,为现场泡沫水泥浆密度确定和施工安全提供指导。

The properties of foam cement are mainly determined by the gas volume fraction of foam. A foam cement slurry with good settling stability was formulated by adding 3%–5% of foaming agent and 0.05%–0.10% of foam stabilizer. The effect of gas volume fraction of foam on the performance of foam cement was studied. An increase in the gas volume fraction of foam increases the viscosity and reduces the filtration rate of the foam cement slurry. The increase in the gas volume fraction also leads to the following results: a linear decrease in the compressive strength of set cement, an increase in gas permeability, and an enhancement of elastoplasticity. Higher compressive strength and better elastoplasticity of set cement can be obtained when the gas volume fraction is controlled around 30%, and the requirements of cementing gas zones can be satisfied.