ZYEB胶囊破胶剂的研制

Preparation of Microcapsulated Gel Breaker ZYEB for Water Base Fracturing Fluids

报道了最高使用温度～ 10 5℃的水基压裂液胶囊破胶剂ZYEB的研制。选择过硫酸铵为破胶剂 ,从 10余种材料中筛选出耐油的聚硫 偏丙乳液、防水的PVDC CP、强度好的硅改性纳米乳液 3种材料复合作囊衣。过硫酸铵粒径为 0 .4～ 0 .9mm ,采用Wurster流化床法制备胶囊破胶剂ZYEB ,介绍了制造过程。对ZYEB的性能作了实验评价 :在蒸馏水中的释放率 ,80℃下 1h为 8.6 % ,80℃下 2h为 36 .9% ;加入 0 .1%ZYEB的HPG/有机硼压裂液 ,在 80℃、170s-1下剪切 2h后粘度为 2 13.8mPa·s,粘度保留率为 6 5 .9% ,在 5 0MPa的流体静压力下保持 2h后粘度保留率 >4 0 % ;在 80℃的压裂液中加入 0 .1%压碎的ZYEB(压力 10MPa ,10min) ,30min内粘度下降 80 %以上 ,2h后粘度为 4 .5mPa·s ;加入 0 .1%ZYEB的压裂液 ,80℃时对渗透率～ 0 .0 18μm2 的岩心渗透率的伤害率为8.7% ,远小于国产破胶剂NEB 1和NEB 2造成的伤害率 ,与进口胶囊破胶剂INTEB造成的伤害率 (7.6 % )大体相当。图 3表 4参 7。

The preparation of microcapsulated gel breaker ZYEB for water base fracturing fluids used below ～105℃ is described. The gel breaker selected is ammonium persulfate (APS) and the capsulating material - oil resistant polysulfide copolymer latex, water proof blend PVDC CP and mechanically strong silicon modified nanosized latex in combination. The encapsulation of APS particles of 0.4-0.9 mm in diameter is conducted by Wurster fluidized bed process. The manufacture of ZYEB is presented. The performance properties of ZYEB are evaluated in laboratory with following results: the release rate of APS from microcapsules in distilled water is of 8.6% at 80℃ in 1 hr and 36.9% at 80℃ in 2 hrs; for a HPG/organic bor fluid with 0.1% ZYEB added, the viscosity after shearing at 80℃ and 170 s -1 in 2 hrs is of 213.8 mPa·s, or 65.9% of initial value, and >40% of initial viscosity is maintained after keeping at hydrostatic pressure 50 MPa in 2 hrs; the viscosity at 80℃ is reduced by >80% in 30 min and is of 4.5 mPa·s in 2 hrs when the ZYEB added has been pressed under pressure 10 MPa in 10 min; the permeability damage to reservoir cores of ～0.018 μm 2 caused by the fluid is of 8.7%, a value slightly higher than that with imported microcapsulated gel breaker INTEB but much lower than that with home made NEB 1 and NEB 2 at similar conditions.