Conventional channeling blocking agent used for thermal recovery is lost easily in low-pressure layers or voided layers and presents poor channeling blocking effect in thick oil layers. In this paper, low-density (<1.1 g/cm3) composite channeling blocking agent was researched and developed to deal with these problems. The effect of water/cement ratio and temperature on the performance of channeling blocking agent was investigated and the properties of channeling blocking agent were evaluated from the aspects of high temperature resistance, pressure resistance, core plugging and steam erosion resistance. It is shown that this low-density composite channeling blocking agent under the temperature of 300 ℃ presents strong steam erosion resistance with volume shrinkage 8.47%, core plugging rate higher than 99% and core breakthrough pressure higher than 0.13 MPa/cm. It was tested on site in 7 well groups. And it is shown that the plugging rate of steam channeling passage is 94.4%. This technology is promising to apply in the middle and late stages of heavy-oil thermal recovery.%针对常规热采封窜剂在低压层或亏空层容易漏失、厚油层封窜效果差等问题,进行了密度小于1.1 g/cm3的低密度复合封窜剂研究.考察了水灰比、温度对封窜剂性能的影响,并对封窜剂耐高温、抗压、岩心封堵、耐蒸汽冲刷等性能进行了评价.实验结果表明:该低密度复合封窜剂在300℃时体积收缩率为8.47%,岩心封堵率大于99%,岩心突破压力大于0.13 MPa/cm,且封窜剂耐蒸汽冲刷性能强.现场试验7井组,汽窜通道封堵率94.4%,表明该技术在稠油油藏热采开发中后期具有广阔的应用前景.
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