驱油用抗温空气泡沫体系研究

Research on Temperature Resist Air Foam System for Flooding

空气泡沫驱技术全面的驱油机理与独特的气源优势令其发展应用前景广泛。为保证该技术在高温油藏的成功应用,开展了抗温空气泡沫体系的相关研究。通过在温度110℃、地层水矿化度6×104mg/L条件下,对10种耐温表面活性剂起泡体积和析液半衰期的考察,筛选出高温泡沫性能良好的阴非离子表面活性剂LS。模拟油藏条件对LS的泡沫性能进行了评价,结果表明,LS在高压密闭条件下能形成比常压下更丰富的泡沫,且多孔介质的持续剪切、空气的持续供给有利于产生丰富的泡沫。向LS中添加浓度0.1%以上的稳泡剂WP,可明显提高其析液半衰期;将0.2%LS+0.1%WP的泡沫体系在110℃、6×104mg/L下老化90 d,析液半衰期仅缩短20%,与大港官80油田原油的界面张力保持在10 2mN/m。同时,空气泡沫体系原油乳化分散性能良好,且能实现油水的彻底分离。

Air foam flooding has very bright future because of its comprehensive displacement mechanism and unique air source predominance.To apply the technique successfully in high temperature reservoir,this paper conducted study on the temperature resist air foam system.By examining the foam volume and liquid separating half-life period of ten temperature resist surfactants at 110 ℃ and 6 × 10^4 mg/L,we screen out the anionic-nonionic surfactant LS which has satisfactory high temperature foam performance.We evaluate the foam performance of LS at reservoir environment and the result shows that LS could form more abundant foam at high pressure seal condition than atmospheric pressure;the persistent shear of porous media and plenty air flow is in favor of LS fully playing its foam performance.By adding foam stabilizer WP whose concentration is beyond0.1%,theliquidseparatinghalf-lifeperiodofLScouldbeevidentlyenhanced.Afteragingunder110 ℃ and6×10^4mg/L for 90 d,the liquid separating half-life period of 0.2%LS＋0.1%WP only shortens by 20%,and its IFT with Guan80 crude oil remains 10^ 2mN/m.Furthermore,the emulsification capability of air foam is satisfactory,oil and water being separated almost completely after standing short length of time.