高温高矿化度CO2泡沫性能实验研究

Experimental Study on Performance of CO2 Foam at High Temperature and High Salinity Conditions

宋 鹤 章 杨 陈百炼 杨昌华 王 庆 张 亮 任韶然

SONG He ZHANG Yang CHEN Bai-Lian YANG Chang-Hua WANG Qing ZHANG Liang REN Shao-Ran

在高温、高矿化度条件下，通过测试起泡剂浓度、温度、矿化度和压力对CO2泡沫性能的影响，筛选出了耐温、耐盐性能良好的表面活性剂作为起泡剂，并通过动态驱替实验，考察了起泡剂在高温、高矿化度条件下的CO2泡沫的流度控制和封堵能力。实验结果表明，HLB值在14~16之间的两性和非离子表面活性剂复配的起泡剂泡沫稳定性较好；高压下（15 MPa）所产生CO2泡沫更为稳定，在100℃下驱替实验所测得最大阻力因子达130，表现出良好的封堵和流度控制性能。泡沫仪测试和驱替实验结果对比表明，泡沫半衰期对阻力因子的影响更为敏感，是衡量泡沫稳定性和封堵能力的主要因素。

CO2 foam has been used as an effective conformance and mobility control agent to prevent early gas breakthrough during CO2 flooding in heterogeneous reservoirs. In this study, the performance of CO2 foams generated using various surfactants was investigated. The effects of surfactant concentration, temperature, salinity and pressure on performance of CO2 foam were studied under high temperature and high salinity conditions prevailed in Zhongyuan oilfield. The performance of the CO2 foam on mobility control was measured via flooding and displacement experiments using sandpacks. The results showed that the complex of amphoteric surfactants LX-8 and nonionic surfactants FL-6 with HLB values between 14 and 16 had good foam stability at high temperature and salinity conditions. The resistance factor of foams generated in sandpacks could reach up to 130 under 100℃ and 15 MPa, indicating that the CO2 foams had good mobility control and sealing capabilities at reservoir conditions. The experimental results also showed that the resistance was more sensitive to half life time of the CO2 foam, which could be the main factor to evaluate CO2 foam’s stability and blocking performance.