煤层气井用非离子聚丙烯酰胺锆冻胶压裂液优选

活性水、瓜胶压裂液是国内煤层气井压裂最常用的压裂液,但活性水压裂液流变性能差,瓜胶压裂液破胶残渣含量高对煤层的伤害大,限制了这两类压裂液在煤层压裂中的应用。为此,针对煤层温度和渗透率低的特点,在分析影响锆冻胶压裂液性能因素的基础上,优选出了适用于煤层气井压裂的非离子型聚丙烯酰胺锆冻胶压裂液配方(0.400%PAM+0.035%ZrOCl2)。通过室内试验对优选出的非离子型聚丙烯酰胺锆冻胶压裂液的性能进行了评价,结果表明,该压裂液具有耐剪切、滤失量低、易破胶、携砂性能好、无残渣、对煤层伤害低、易返排的特点,适用于低温煤层压裂。 

Research on Nonionic Polyacrylamide Zirconium Gel Fracturing Fluids in Coalbed Methane Gas Wells

Active water and guar gum are widely used for coalbed methane fracturing in China.Nevertheless,the application of these two types of fracturing fluid was limited due to poor rheological properties of active water and severe formation damage of guar gum fracturing fluid.Considering the temperature and low permeability of coalbed,the formulation of nonionic polyacrylamide zirconium gel fracturing fluids suitable for coalbed mechane fracturing was selected based on the analysis on the effects of different factors on the zirconium gel.The formulation is 0.4%PAM+0.035%ZrOCl2.The performance of the optimized formulation of nonionic polyacrylamide zirconium gel fracturing fluids was evaluated through laboratory experiments,and the results showed that,the formulation had the characteristics of shearing resistance,low filter loss,easy breaking,good proppant carrying capacity,non-residue,low formation damage and easy flowback.It is suitable for the coalbed gas reservoirs fracturing.