抗高温发泡体系的研制及性能评价

目前随着油气钻探井深的增加，泡沫钻井液的抗温性成为泡沫钻井的限制条件之一。不同类型表面活性剂之间存在协同增效作用，因此可通过表面活性剂之间的复配实现泡沫性能的稳定提升。笔者选用了6种表面活性剂，确定最佳发泡浓度是0.6%，以泡沫综合值为泡沫性能指标，对泡沫性能较好的4种表面活性剂进行了耐盐性能、抗温性能评价。实验表明，十二烷基二甲基氧化铵（OA）随盐度的增加，泡沫综合值曲线变化平稳，耐盐性较好；α-烯烃磺酸钠（AOS）在100℃以上时泡沫综合值较高，耐温能力较好。再对AOS和OA以不同浓度比例复配，得到2者最佳配比是4:1，复配体系最佳发泡浓度为0.4%。通过BZY-1表面张力仪对复配体系评价，表明复配发泡剂表面张力值随温度升高而降低，复配发泡剂体系更加稳定；抗温性评价表明复配体系在150℃以下时协同作用明显，耐温性效果较好，在100℃时泡沫综合值可以达到21.96×104 mL ·s。 

Formulation of High Temperature Foaming Drilling Fluid and Performance Evaluation

As well depth is becoming deeper, high temperature stability of foam mud becomes one of the restricting factors to foam drilling. Synergistic effect between different types of surfactants can be used to enhance the high temperature stability of foams. In our study six kinds of surfactants at the optimum concentration of 0.6% have been chosen to formulate a foam. Among these six surfactants, four of them have better foaming performance, and were evaluated for their ability to resist salt contamination and high temperature stability. The evaluation results showed that dodecyl dimethyl ammonium oxide (OA) had a stable foam comprehensive value at varied salt concentration, indicating that OA has good salt contamination resistance. At 100 ℃ or above, the α-sodium olefinsulfonate (AOS) had high foam comprehensive value, indicating that AOS has better high temperature stability. Study on the compounding of OA and AOS showed that the optimum ratio of the two was AOS:OA = 4:1. The optimum concentration of the compounded AOS and OA was 0.4%. Evaluation test on a BZY-1 surface tensiometer showed that the surface tension of the compounded surfactants is decreasing with temperature, indicating that when temperature is increasing, the foam fluid formulated with the compounded surfactants is becoming more and more stable. It was found in the evaluation test that the synergistic effect of the different surfactants reaches maximum at 150 ℃, and the foam comprehensive value at 100 ℃ reached 21.96×104 mL·s, indicating that the compounded surfactants have good high temperature stability.