摘要
针对常规压裂液体系有机金属离子交联剂毒性较大且在碱性条件下不可避免的会对地层产生二次污染以及非金属离子交联剂形成的压裂液成胶速度慢且不抗剪切的问题，本文制备了由一种非金属离子交联体系形成的低毒性压裂液，通过对影响凝胶性能的主要因素进行分析得到了压裂液的最佳配方，并考察了压裂液的耐温抗剪切性能和破乳性能。实验结果表明：当稠化剂含量为0.075%、pH值调节剂 0.015%、乙醇1%、促凝剂0.020%～0.025%之间、交联剂0.25%、氯化钾 0～2%之间时，可制备出成胶时间短、耐温抗剪切性能和破胶性能优良的压裂液。该压裂液体系的成胶时间约为150 s左右，成胶后压裂液初始黏度为1529.0 mPa·s，在100℃ 、170 s-1下剪切60 min、90 min、120 min后的黏度分别为 259.9 mPa·s、197.4 mPa·s和166.8 mPa·s；90℃下向压裂液中加入0.03%过硫酸钾破胶剂，3 h后完全破胶，破胶液清澈透明，黏度为1.07 mPa·s。所研制的交联剂不含任何高价金属离子，减小了压裂液对地层的伤害。图1表5参11
Abstract
The conventional metal crosslinked fracturing fluid system have some weakness, such as great toxicity and the produced second pollution to the formation duiring crosslinking process at alkaline condition;while the non-metal ion crosslinked fractureing fluid system also has some problems, such as slow gelling rate and poor shear resistance performance. In the paper, a low toxicity fracturing fluid with a novel cross-link agent system was prepared, the best formula of the fracturing fluid were obtained by analyzing the main factors affecting gel performance, the high temperature and shearing resistance and demulsification performance were investigated. The experimental results showed that, when the thickener content was 0.15%, the amino sulfonic acid content was 0.15%, the ethanol content was 1%, the of coagulator content was 0.020%—0.025%, the crosslinking agent content was 0.25% and the potassium chloride content was 0—2%, the fracturing fluid with the excellent performance could be prepared. the gelling time of the optimal fracturing fluid was about 150 s, and the initial viscosity after gelling was of 1529.0 mPa·s. When the fracturing fluid was continuously sheared at the temperature of 100℃ and the shearing rate of 170 s-1 for 60 minutes, 90 minutes and 120 minutes, respectively, the viscosity was of 259.9 mPa ?s, 197.4 mPa ? s and 166.8 mPa ?s, respectively，indicating that the fracturing fluid had strong high temperature and shearing resistance. The gel can be broken totally with 0.03% of potassium persulfate at the temperature of 90℃within 3 hours. The gel-broken fluid was clear, and the viscosity was only 1.07 mPa·s. The fracturing fluid system did not contain any toxic metal ions, reducing the damage to formation.
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