一种低黏度乳化酸性能研究

Performance Properties of a Low Viscosity Emulsified Hydrochloric Acidizing Fluid

分别以加有有机溶剂的有机酸胺盐和脂肪胺盐为乳化剂和助乳化剂,加量分别为酸油总质量的0.8%和0.5%,将加有2%缓蚀剂、1%铁离子稳定剂的20%盐酸乳化在柴油中,制得了低黏度的乳化酸。酸油体积比70:30的乳化酸在温度30～70℃下显示假塑性流体特性,在120℃、1701/s剪切60min,黏度由约26mPa.s逐渐下降到约15mPa.s。酸油体积比70:30和80:20的乳化酸在室温放置48小时或在90℃放置4小时均无酸析出,在90℃下与大理石反应1小时后才开始析出酸,电导率测定值和在偏光显微镜下观测的酸滴直径均证明了酸油乳状液的稳定性。用旋转岩盘实验装置在7.5MPa、90℃下测定,在70:30的乳化液与含碳酸钙≥99%的岩心之间的反应中,随盐酸浓度减小(6.122～3.364mol/L),H+有效传质系数减小(2.376×10-6～7.980×10-7cm2/s),反应速率减小(5.75×10-6～1.51×10-6mol/cm2.s)。由实验数据导出了该乳化酸与碳酸盐岩反应动力学方程。

A low viscosity emulsified acidizing fluid（EAF） was prepared from 20% hydrochloric acid with 2% corrosion inhibitor and 1% ferroferric ions stabilizer added and diesel oil as dispersive medium at the presence of an organic acid amine salt in solvent as emulsifier and a fatty amine salt in solvent as emulsification promotor at dosages of O. 8% and O. 5% of total mass of acid and diesel, respectively. The EAF of acid to diesel volume ratio （ADVR） 70：30 demonstrated pseudoplaticity at 30--70℃ and its viscosity decreased from about 26 mPa·s to about 15 mPa·s in 60 min shearing at 120℃ and 170 1/s. No free acid was separated from the EAF of ADVR =70：30 and 80：20 in standing at ambient temperature over 48 hrs or at 90℃ over 4 hrs;the EAF started to release free acid after 1 hr reaction with marble sample at 90℃ ; the good stability of the EAF was evidenced by electric conductance determinations and acid droplet size measured under polarized light microscopy. In reactions of EAF of ADVR = 70：30 with a reservoir core composed of 〉 99% calcium carbonate conducted on a rotating disc experimental apparatus at 90℃ and 7.5 MPa, the mass transfer coefficient of hydrogen ion was decreased from 2. 376 × 10 ^-6 to 7. 980× 10 ^-7 cm^2/s and the reaction rate from 5.75 × 10 ^-6 to 1.51 × 10 ^-6 tool/ cm^2· s. A kinetic equation was deduced from these experimental data for the reaction of the EAF with carbunatestune sample.