改性聚乙烯醇压裂液的制备与性能研究

Preparation and Evaluation on Modified Polyvinyl Alcohol Fracturing Fluid

胡孝勤 张霖杰 唐金波 张 熙

HU Xiaoqin，ZHANG Linjie，TANG Jinbo，ZHANG Xi

为提高聚乙烯醇压裂液耐温抗剪切性能， 采用改性纤维素与聚乙烯醇的共混物作为稠化剂、 有机钛为交联剂制备改性聚乙烯醇压裂液， 研究了共混改性聚乙烯醇稠化剂的组成、 压裂液中稠化剂与交联剂浓度、 温度、 pH值对压裂液性能的影响， 对比了聚乙烯醇压裂液与改性聚乙烯醇压裂液的耐温抗剪切性能。结果表明： 采用改性纤维素对聚乙烯醇稠化剂进行共混改性， 可提高稠化剂的增黏能力和所配制的压裂液耐温抗剪切性能， 稠化剂中改性纤维素含量以 40%为宜； 改性聚乙烯醇压裂液的组成和 pH值对压裂液性能影响显著， 适宜的改性聚乙烯醇压裂液配方为： 稠化剂加量 1.8%数 2%、 交联剂加量 0.9%数 1%、 pH 值 7数 9， 该改性聚乙烯醇压裂液在120℃、 剪切速率 170 s-1下连续剪切 90 min后的黏度仍可保持在 50 mPa·s以上， 能满足油藏温度低于 120℃油层的应用要求。图4表2参10

To improve temperature-resistant and shear-resistant properties of polyvinyl alcohol fracturing fluid，a modified polyvinyl alcohol fracturing fluid was prepared using the mixture of polyvinyl alcohol and the modified cellulose as thickening agent and organic titanium as crosslinker. The effects of the composition of the thickening agent，the content of the modified polyvinyl alcohol（thickening agent）and the cross linker，temperature and pH value on properties of the fracturing fluid were investigated. The temperature-resistant and shear-resistant properties of the modified polyvinyl alcohol fracturing fluid were compared with that of polyvinyl alcohol fracturing fluid. The results showed that the thickening ability of the thickening agent and the temperature-resistant and shear-resistant properties of the modified polyvinyl alcohol fracturing fluid after adding modified cellulose were significantly improved compared with that of polyvinyl alcohol fracturing fluid. Besides，the properties of the thickening agent with mass fraction of 40% the modified cellulose were optimum. The properties of the fracturing fluid were obviously affected by the composition of the modified polyvinyl alcohol fracturing fluid and pH value. The optimum compositions of the fracturing fluid were as follows：1.8%—2% thickening agent，0.9%—1% crosslinker，and the pH value was in range of 7—9. Under conditions of constant temperature of 120℃ and shear rate of 170 s-1，the viscosity of the modified polyvinyl alcohol fracturing fluid was still over 50 mPa·s after continuous shearing for 90 min，showing good temperature-resistant and shearresistant properties，which indicated that the odified polyvinyl alcohol fracturing fluid could meet the requirement of fracturing construction when the reservoir temperature was below 120℃.

10.19346./j.cnki.1000-4092.2017.01.006