CO₂泡沫压裂可以减少储层伤害，有助于非常规油气藏增产开发，但目前缺少定量评价泡沫压裂液碳水比对导流能力影响程度的方法，泡沫压裂液体系碳水比优选存在不足。为优选适用于玛湖凹陷砾岩储层的CO₂泡沫压裂液体系，开展模拟储层条件下不同碳水比泡沫流体作用下支撑剂嵌入实验，得到各嵌入深度区间的比例，建立考虑支撑剂非均质嵌入的导流能力模型，计算获得不同泡沫流体提高导流能力的效果并分析其作用机理。结果表明：使用CO₂替代部分水基压裂液，可以降低支撑剂的嵌入程度；随着CO₂比例升高，泡沫流体提高导流能力的效果逐渐减弱并达到上限，模型导流能力较水基提高约12%；碳水比7∶3时低黏土含量（黏土矿物含量< 20%）试件导流能力提高达到上限，高黏土矿物含量试件（黏土矿物含量≥20%）的导流能力受碳水比的影响更敏感，达到上限时碳水比较低；CO₂泡沫压裂液可以提高支撑裂缝-缝周边地层系统的渗流能力。研究成果可为CO₂泡沫压裂液体系碳水比优化提供参考。

CO₂ foam fracturing can reduce reservoir damage and contribute to the stimulation of unconventional oil and gas reservoirs. However, there needs to be more quantitative methods to evaluate the influence of the CO₂-H₂O ratio of foam fracturing fluid on the conductivity, and the optimization of foam fracturing fluid system is insufficient. To select the CO₂ foam fracturing fluid system suitable for the conglomerate reservoir in the Mahu Basin, proppant embedment experiments were carried out with the treatment of foam fluid with different CO₂-H₂O ratios at simulated reservoir conditions, and each interval of embedment depth was obtained. A conductivity model considering the heterogeneous proppant embedment was established to calculate the effects of different foam fluids on improving the conductivity and analyze its mechanism. The results show that using CO₂ to replace part of the water-based fracturing fluid can reduce the degree of proppant embedment. With the increase of the CO₂ -H₂O ratio, the effect of improving the conductivity weakens and reaches the upper limit gradually, increasing by about 12% compared with that of water-based fracturing fluid. When the ratio is 7∶3, the conductivity of samples with low clay content (< 20%) increases to the upper limit. However, the conductivity of samples with high clay mineral content (≥20%) is more sensitive to the influence of the CO₂-H₂O ratio, and the upper limit is lower. CO₂ foam fracturing fluid can improve the hydrological capacity of the propped fracture-formation system. The research results can reference the CO₂-H₂O ratio optimization of the CO₂ foam fracturing fluid system.