新型超高温压裂液的流变性能

利用羟丙基瓜胶和部分水解聚丙烯酰胺为复合增稠剂,引入具有延缓释放功能有机锆作为交联剂,开发新型超高温水基压裂液,并考察其流变性能。结果表明:引入复合增稠剂和具有延缓释放功能有机锆,能优化压裂液交联网络的结构;引入具有延缓释放功能有机锆使得压裂液在高温剪切过程中产生二次交联,从而极大提高压裂液的温黏性;在恒温200℃和剪切速率170 s-1条件下,连续剪切2 h以上,压裂液的剪切黏度大于80 mPa.s,可满足大庆油田4.7～5.0 km深层致密高温气藏增产改造的需要。

Rheological behaviors of a novel ultra-high temperature fracturing fluid

By introducing the complex of hydrolyzed polyacrylamide and hydroxypropyl guar as the thickener and organic zirconium as the delayed crosslinker,a novel ultra-high temperature fracturing fluid was developed and its rheological behaviors were investigated.The results show that the crosslinked network structure of this new type fracturing fluid is optimized by introducing the complex thickener and delayed crosslinker of organic zirconium.In particular,by introducing organic zirconium as the delayed crosslinker,the fracturing fluid is crosslinked once again during the process of shearing at high temperature.As a result,the high temperature resistance of the fracturing fluid is improved significantly.The shear viscosity of this novel fracturing fluid is larger than 80 mPa·s even if this fracturing fluid is sheared more than two hours under the shear rate of 170 s-1 and at the temperature of 200 ℃.This suggests that this novel fracturing fluid can be applied to stimulate the tight and high temperature natural gas reservoirs with the depth of 4.7-5.0 km in Daqing Oilfield.