纳米二氧化硅改性有机硼交联剂的制备与性能评价

Preparation and performance evaluation of organic boron crosslinker modified by nanosilica

为重复利用有机硼交联剂制备的压裂液,将N-(β-氨乙基)-γ-氨丙基三甲氧基硅烷表面改性的纳米二氧化硅与乙二醇丁醇硼酸酯发生硼酰化反应,制得纳米二氧化硅有机硼交联剂(NSOBCL),对制备条件进行了优化,通过红外光谱仪表征了NSOBCL的结构,研究了NSOBCL和破胶液配制压裂液的耐温抗剪切性。结果表明,制备有机硼交联剂中间体时,N,N-二胺乙基丙酸甲酯单体与表面氨基改性二氧化硅的最佳质量比为54∶1;制备NSOBCL时,硼酸脂与交联剂中间体的最佳质量比为1∶2。红外表征结果表明合成产物与预期结构相符。0.25%羟丙基胍胶与0.3%NSOBCL等配制的压裂液耐温抗剪切性能较好,在80℃、170 s^(-1)下剪切60 min的黏度约为178 mPa·s;破胶剂过硫酸铵可使压裂液在80℃、120 min内完全破胶,破胶液黏度为2.68 mPa·s。NSOBCL可用于压裂液破胶液的再次交联。在破胶液中补加0.25%羟丙基胍胶和0.4%NSOBCL,于80℃、170 s^(-1)下剪切60 min后的黏度为175 mPa·s;而现场使用的JL-13交联剂无法满足重复使用的要求。

In order to reuse fracturing fluid prepared by organic boton crosslinker,nanosilica organic boron crosslinker(NSOBCL) was prepared through the reaction between silica nanoparticle modified by N-(amino-ethyl)-amino-propyl trimethoxy silane and ethylene glycol butanol borate.The preparation condition was optimized and the structure of NSOBCL was characterized by infrared spectrometer.The temperature resistance and shearing resistance of fracturing liquid prepared by NSOBCL and breaking liquid were studied.The results showed that the optimum mass ratio of monomer of N,N-diaminoethyl propionate methyl ester and surface amino modified nano silicon dioxide was 54∶1 during the preparation of organic boron crosslinker intermediate,and that of Borate and crosslinker intermediate was 1∶2 during the preparation of NSOBCL.The results showed that the structure of the product with expectations through infrared spectrum.The fracturing fluid prepared by 0.25% hydroxypropyl guar gum,0.3% NSOBCL and other additives had good temperature and shearing resistance,whose viscosity was 178 mPa·s after shearing 60 min at 80 ℃ and 170 s^(-1).The fracturing fluid could completely break at 80 ℃ and 120 minutes after adding ammonium persulfate,and the viscosity of gel breaking liquid was 2.68 mPa·s.In addition,NSOBCL could be used for the secondary crosslinking of fracturing fluid breaking liquid.After adding 0.25% hydroxypropyl guar gum and 0.4% NSOBCL to breaking liquid,the viscosity of the new fracturing fluid was 175 mPa·s after shearing 60 minutes at 80 ℃ and 170 s^(-1).On the contrary,JL-13 crosslinker used in the field could not achieve the purpose of reuse with the same amount.