微悬浮乳液堵调剂性能研究

Laboratory study on micro suspension emulsion plugging agent

生产实践证实,常规化学堵调剂对层间渗透率级差大于3的地层不能达到理想的调剖和堵水效果.以油溶性树脂为主剂,并添加乳化剂、稳定剂及其他助剂,经乳化机剪切和乳化后,制备成粒径为1～5 μm且性能稳定的水包油微悬浮乳液堵调剂.通过实验确定了该堵调剂的最佳配方：50％～60％（表示质量浓度,以下同）树脂＋0.35％～0.40％十八烷基三甲基氯化铵或0.35％～0.40％十二烷基苯磺酸钠＋0.1％羟甲基纤维素＋0.10％～0.15％氯化钙＋1％～5％石蜡＋水;同时还确定了针对该堵调剂的破乳配方,即当乳化剂为十八烷基三甲基氯化铵时,破乳剂宜选用质量浓度为2％～3％的氢氧化钠水溶液,当乳化剂为十二烷基苯磺酸钠时,破乳剂宜选用质量浓度为3％～5％的氯化钙水溶液.通过对微悬浮乳液堵调剂的油溶率、酸溶率和粒径等各项指标进行性能测试,结果反映出该堵调剂具有良好的选择性及注入性.岩心驱替实验结果表明,该堵调剂的突破压力梯度达26 MPa/m,堵水率大于97％,耐水冲刷性能优于常规凝胶,并且适用于渗透率级差为7的岩心.

It is recognized that the normal chemical plugging agent cannot plug water and control profile effectively in formations with permeability ratio data more than three. Stable oil-in-water micro suspension emulsion （grain size 1 ~5 μm） was prepared from main material oil-soluble resin, emulsifier and stabilizer through disperse mill. The optimal formula was determined as follows： 50% -60% resin ＋0.35% -0.40% octadecyl trimethyl ammonium chloride or 0.35% 0.40% sodium benzenesulfonat ＋0.1% CMC ＋0.10%~0.15% calcium chloride ＋1%-5% SL＋ water. Demulsifier formulation were also determined, 2% -3% aqueous solution of sodium hydroxide and 3%-5% calcium chloride solution were used for cationic emulsion and anionic emulsion corresponding. Viscosity, electron microscopy analysis of grain size, acid solubility, oil solubility tests were also carried out. Performance test shows that it has high temperature range and good injection and selectivity performance. Core flooding test shows that the breakthrough pressure gradient was 26 MPa/m, the plugging rate is greater than 97%, it kept high plugging rate after large amount ofwater flooding and it had good profile control performance for heterogeneous reservoir with the permeability ratio data being of seven.