超高温改性瓜胶压裂液性能研究与应用

Research and Application of Ultra-High Temperature Fracture Fluids

针对目前压裂井越往深井发展地层温度越高这一问题,研究开发了一种由耐高温改性瓜胶、有机硼锆交联剂和温度稳定剂等形成了超高温压裂液体系,即0.55%超高温改性瓜胶+1%温度稳定剂BA1-26+0.5%助排剂BA1-5+0.5%黏土稳定剂BA1-13+0.02%杀菌剂BA2-3+2%KCl+0.6%交联剂。用AFM、SEM观察了压裂液交联前后的微观结构,并考察了压裂液的相关性能。实验结果表明,超高温压裂液具有良好的抗剪切能力,180℃、170 1/s下剪切2 h后,黏度仍保持在150 mPa.s以上;通过调节pH可使超高温压裂液的成冻时间控制在3～15 min之间,有利于深井施工;交联前压裂液的线形结构有利于提高降阻性能,交联后压裂液的三维结构有利于携砂。破胶液外观清澈透明、黏度较低(<6 mPa.s)、表面张力低(为28.6 mN/m),残渣率为10.6%。现场实施进一步证明研制的超高温压裂液能满足180℃地层的压裂要求。

Aimed at the problem that the subterranean temperature is more and more high,a new type fracturing fluids（FFs） with high temperature resistance was developed,composed of 0.55% modified guar gum,1% temperature stabilizer BA1-26,0.5% cleanup reagent BA1-5,0.5% clay stabilizer BA1-13,0.02% bactericide BA2-3,2%KCl and 0.6% crosslinker reagent（a complex including organic boron and zirconium.The microstructure of the gelling was characterized by AFM and SEM.At the same time,the related performance of the FFs was investigated.The results showed that,The FFs had good shear-resistance,the viscosity of the FFs could keep above 150 MPa·s after shearing at 170 1/s for 2 hours.The gelling time of the FFs could be controlled at the range of 3 to 15 minutes through adjusting pH of the system,which is advantageous to the transportation of the proppant.The linear structure of the FFs before gelling was favorable to improve the scrape resistance of the FFs;while the network structure of the FFs after gelling ensured optimum encapsulation of fine solids.After breaking gelling,the viscosity of the FFs was below 6 mPa·s,the surface tension was 28.6 mN/m and the rate of residue was 10.6%.The ultra high temperature FFs system was applied to the field successfully,which proved the FFs system could match the need of the well with the temperature above 180℃.