CO_2/N_2开关型泡沫钻井液用起泡剂的合成及应用

Synthesis and application of switchable CO_2/N_2 foaming agent used in foam drilling fluid

以十二胺和N，N-二甲基乙酰胺为主要原料，采用缩醛法合成了一种CO2／N2开关型表面活性剂N′-十二烷基-N，N-二甲基乙脒（DMAAB-12）作为泡沫钻井起泡剂。采用FTIR和1HNMR等方法对DMAAB-12进行了结构表征，并测试了DMAAB-12的泡沫性能及可循环能力。表征结果显示，合成产物的结构与设计相一致。实验结果表明，当x（DMAAB-12）=0．4％时，溶液的发泡体积为514mL，泡沫半衰期为523S，表现出良好的泡沫性能；以DMAAB-12为起泡剂在室内可实现泡沫的循环利用，交替通人CO2／N2循环10次后，泡沫的发泡体积由753mL降至561mL，泡沫半衰期由225s降至164S，仍具有较好的泡沫性能，可实现泡沫的循环利用。

A switchable CO2/N2 foaming agent, N＇-dodecyl-N, N-dimethyl acetamidine（DMAAB-12） which could be used in foam drilling fluid, was synthesized through acetalation from dodecylamine and N, N-dimethylacetamide, and was characterized by means of FTIR and 1H NMR. Its foaming performance and recyclability were investigated. The characterization results showed that the structure of DMAAB-12 was consistent with the design. The experimental results indicated that, when x（DMAAB- 12） 0.4%, the foaming volume and foam half-life reached 514 mL and 523 s, respectively. DMAAB-12 can be reused indoors. After it was recycled 10 times, the foaming volume and half-life decreased only from 753 mL to 561 mL and from 225 s to 164 s, respectively.