超稠油复合降黏剂SDG-3的研究和应用

Research and Application of Composite Viscosity Reducer SDG-3 Aimed at Ultra-heavy Oil

采用脂肪醇聚氧乙烯醚、Na OH、氯乙酸、醇和混合芳烃为原料,制备了一种高效复合降黏剂SDG-3。考察了其分散原油重组分能力、界面活性、乳化性能、降黏性能、耐温耐盐性和破乳性能。结果表明:SDG-3能分散超稠油中重组分,质量分数1%的SDG-3在不含水条件下使原油黏度从181 000 m Pa·s降低至81 989 m Pa·s,降低了54.7%;使地层水-超稠油的界面张力由22.00 m N/m降低至0.32 m N/m,对超稠油乳化效果优于常规水溶性降黏剂,形成的O/W乳状液平均粒径为2.5μm,对委内瑞拉、中海油、塔河超稠油降黏率均达到99.0%以上,优于常规油溶性降黏剂的降黏率(72.6%),耐盐度达2.2×105mg/L,耐高温达140℃,与油田破乳剂配伍性好。在塔河油田进行现场实验期间,日平均节约稀油率66.6%,平均提高稠油采收率14.4%。

An new effective composite viscosity reducer SDG-3 was prepared with primary alcobol ethoxylate,sodium hydroxide,chloroacetic acid,alcohols and mixed aromatics as raw materials. And the ability to disperse heavy oil compositions,interfacial activity,emulsifying property,viscosity reducing capability,salt and heat resistance,and demulsification of SDG-3 were evaluated. Experimental results show that SG-3 can disperse heavy compositions in the ultra-heavy oil. When SDG-3 with mass fraction of 1% was added into the ultra-heavy oil without the presence of water,the viscosity of the ultra-heavy oil reached 81 989 m Pa·s,which was a decrease of 54. 7% compared with that without SDG-3（ 181 000 m Pa·s）. Meanwhile,when SDG-3 was added into water with a high salinity of2. 2 × 10^5 mg / L and heavy oil with viscosity of 1. 81 × 10^5 m Pa·s,the oil-water interfacial tension（ IFT）（ 0. 32 m N/m） of this system was much lower than that of the system without addition of SDG-3（ 27 m N / m）. SDG-3 exhibited good emulsification capability compared with water-soluble viscosity reducer,and the average droplet size of the oil in water（ O / W） emulsion was 2. 5 μm. Additionally,the degree of viscosity reduction（ DVR） of SDG-3 for Venezuela,CNOOC and Tahe heavy oils allreached over 99%,which was better than that of traditional oil-soluble viscosity reducer（ 72. 6%）.SDG-3 had an excellent compatibility with the oilfield demulsifier and its salt and heat resistance was2. 2 × 10^5 mg / L and 140 ℃,respectively. Subsequently,field tests of SDG-3 were carried out in the Tahe oilfiled. The results indicated that SDG-3 could make average save thin oil rate reach 66. 6 %,and enhance oil recovery with an improvement of 14. 4% on average.