煤层气井清洁压裂液破胶剂的筛选

为解决清洁压裂液在煤层气井中的破胶问题,通过考察破胶剂的种类、温度、用量及pH值对破胶时间的影响,筛选了4种适合于不同压裂深度的煤层气井的新型温敏化学破胶剂——PJJ-25、PJJ-30、PJJ-35和PJJ-40。结果表明:这4种破胶剂用量为0.02%~0.03%;破胶时间在0.5~5 h之间可控制;破胶后体系粘度小于3 mPa.s;表面张力低于30 mN/m;残渣低于0.1%。实践证明,这4种破胶剂均有良好的破胶效果,破胶液与地层的配伍性良好,且对煤层伤害较轻。

The selection of gel breaker for clearing fracturing fluid in CBM well

To solve gel breaking problems in CBM well,through studying the influence of sort,temperature,dos-age and pH value on gel-breaking time,four new type of temperature-sensitive chemical gel breakers—PJJ-25,PJJ-30,PJJ-35 and PJJ-40 were screened for different depths of CBM well.The research showed that the dosage of such gel breakers is 0.02 %~0.03 %,gel-breaking time can be controlled between 0.5~5 h,after gel breaking the viscosity less than 3 mPa.s,surface tension less than 30 mN/m,residue content below 0.1 %.Practice has proved that the adopted gel breakers have satisfactory gel breaking results.The gel-breaking liquids have good compati-bility with the formation,and the damage to coal bed is small.