焦化防砂效果的影响因素分析

焦化防砂是一种防砂新技术 ,采取向地层内注入热空气使原油在高温下发生氧化裂解生成焦炭 ,从而将地层砂固结。通过实验的方法对影响焦化防砂效果的因素进行了分析。实验结果表明 ,注入热空气的最高温度是影响抗压强度的主要因素之一 ,只有在适宜的温度范围内 ,才能高效地得到固结的岩样 ;热空气达到预定的最高温度后 ,应该持续一定的时间 ,以保证一定的反应深度。化学反应前的温升速度与岩样抗压强度无关 ,在达到反应温度后维持足够的反应时间 ,所得岩样就能得到一定的抗压强度。空气流量越大 ,化学反应速度越快 ;当注入的空气量超过了化学反应所需的流量时 ,流量对抗压强度的影响不大。当反应生成适量的胶结物时 ,砂粒粒径越大 ,其固结抗压强度越高。此外 ,经过焦化处理的岩样的抗压强度还与砂粒粒度、油砂体积比、原油性质等因素有关。

Analysis of affecting factors on efficiency of warm-air coking and sand control

Warm air coking sand control technique is a new technology. When the warm air is injected into the formation, crude oil may be split at high temperature to produce coke, which can consolidate the formation. The mechanism of warm air coking and sand control was discussed, and factors affecting the coking efficiency were analyzed. The results show that the highest temperature of the injected hot air is one of the major factors affecting the compression strength of cores. The treatment time for sand control must be limited in a proper range for suitable chemical reactivity. The more the air flow rate is,the faster the chemical reactions will be. The flow rate of air has no affection on compression strength reaction, when the excess of it over the requirement of chemical reaction. Warm air coking sand control technique is suitable for heavy oil reservoir. The compression strength of the treated cores has some relations with the sand size,oil sand ratio and oil properties.