胶质气体泡沫的起泡性能及封堵能力研究

Foaming Property and Blocking Ability of Colloidal Gas Aphron

为揭示稳泡剂黄原胶(XG)对胶质气体泡沫(CGA)性能的影响规律及胶质气体泡沫的封堵行为特征,在高速(3500 r/min)搅拌下用起泡剂(甜菜碱表面活性剂)和XG制备了胶质气体泡沫,研究了XG浓度对CGA起泡性能、黏度和泡沫粒径的影响,考察了CGA对均质、非均质填砂管的封堵性能。研究结果表明,随XG浓度增大,CGA待起泡液黏度、CGA低剪切速率黏度和泡沫析液半衰期增加,起泡体积降低。XG质量浓度为6 g/L、表面活性剂质量浓度为4 g/L时,CGA的析液半衰期为46 h,起泡体积为345 m L,低剪切速率黏度大于40 Pa·s。XG浓度相同时,CGA平均直径随静置时间延长而增大;静置时间相同时,CGA平均直径随XG浓度增加而降低;CGA粒径膨胀速率随XG浓度的增加而变缓。CGA拥有较厚的液相保护外壳,不存在Plateau边界,稳定性较高。CGA溶液对均质及非均质模型均有较强的封堵作用,封堵均质、非均质填砂管的最大驱替压力分别为7.52和7.89 MPa,CGA可显著改善地层非均质性,封堵调剖能力较强。

In order to reveal the effect of xanthan gum on the performance of colloidal gas aphron （CGA） and blocking behavior characteristics of CGA, the CGA was prepared by betaine surfactant and xanthan gum solution under the condition of high speed stirring. The effect of xanthan gum concentration on the foaming ability, viscosity and bubble size was studied, the plugging effect of CGA was investigated by homogeneous and heterogeneous sandpacks. The experiment results showed that with the increase of xanthan gum concentration, the viscosity of awaiting foaming solution, low shear rate viscosity of CGA and drainage half-life increased, and foaming volume decreased. The drainage half-life and foaming volume of CGA was 46 hrs and 345 mL respectively, and its low shear rate viscosity was greater than 40 Pa. s when xanthan gum concentration was 6 g/L and surfactant concentration was 4 g/L. When xanthan gum concentration was the same, the average diameter of CGA increased with the extension of standing time. When standing time was the same, the average diameter of CGA decreased with increasing xanthan gum concentration. Diameter swelling rate of CGA slowed down with the increase of xanthan gum concentration. Micrographs showed that CGA owned a unique thick aqueous protective shell, bubbles existed in separate spheres and there was no plateau boundary around bubbles which stability was higher. CGA had a strong plugging effect toward homogeneous and heterogeneous model. The maximum displacement pressure of homogeneous and heterogeneous model reached 7.52 and 7.89 MPa respectively. CGA could remarkably improved heterogeneity of reservoir and showed a better profile control ability.