复合表面活性剂酸液助排剂FOC及其应用

测定分属4种类型的10余种常用表面活性剂的表/界面张力和润湿性(相对润湿角)。根据测试结果并考虑相互间的协同效应和价格,研发了由20%降低表面张力能力强的FSK(临界胶束浓度FSK水溶液的表面张力为25.3 mN/m)、40%降低界面张力能力强的CTAB(临界胶束浓度CTAB水溶液与煤油间的界面张力为2.0 mN/m)、10%可增加接触角的OP-10(1.6 g/L OP-10的20%盐酸溶液在石英砂上的接触角为69.1°)及辅助表面活性剂组成的高效助排剂FOC。FOC在酸液中与各种添加剂配伍,表/界面活性高,加入200 mg/L FOC的20%盐酸溶液的表面张力为26.3 mN/m,与煤油间的界面张力为2.1 mN/m,助排率为85.9%,热稳定性好。74低渗区块741313油井经检泵、洗井作业后受到严重水伤害,产出液含水100%,注入含0.5%FOC的前置液、8%盐酸及8%/2%土酸 5%醋酸后,含水降至51.6%,日产油恢复至4.8 t。图9表2参5。

Combinational Surfactant FOC as Cleaning-Up Agent for Acidizing Fluids and Its Application

The surface and interfacial tension and the wettability(relative contact angle on quartz) of more than 10 standard surfactants of 4 different types are determined experimentally and,based on the data obtained with the synergistic effects and the cost taken into consideration,a high efficiency cleaning-up agent,FOC,for reservoir blockage relieving/acidizing fluids is developed and composed of 20% fluorocardonic surfactant FSK,capable of reducing water surface tension to 25.3 mN/m at its CMC,40% cationic surfactant CTAB,capable of reducing interfacial tension with kerosene to 2.0 mN/m at its CMC,10% nonionic surfactant OP-10,capable of raising contact angle on granular quartz of 20% hydrochloric acid at concentration 1.6 g/L,and supplementary surfactant(s).FOC is compatible with various additives in various acids,possesses high surface and interfacial activity as shown by surface tension of 26.3 mN/m,and interfacial tension with kerosene of 2.1 mN/m for 20% hydrochloric acid with 200 mg/L FOC added,gives a high cleaning-up rate of 85.9%,and is good in thermal stability.Oil well 741313 at low permeability block 74 was seriously damaged by water invasion in pump maintenance and well washing jobs to an extent of 100% watercut and was treated by injecting a 0.5% FOC pad fluid,an 8% hydrochloric acid and an 8%/2% mud acid and 5% acetic acid slugs with 0.5% FOC added in turn;this treatment led to a reduction of watercut to 51.6% and a recovery of oil output 4.8 t/d.