实现快速排液的纤维增强压裂工艺现场应用研究

川西新场气田在压后排液测试及采气初期，常常出现支撑剂回流返吐的问题，给压裂井测试和正常输气造成不利影响。为此，文章进行了不同闭合压力、不同压裂液粘度和不同纤维浓度的支撑剂稳定性测量实验，结果表明，加入纤维后的支撑剂充填层的临界出砂流速提高了10倍以上，稳定性显著增强，对预防支撑剂回流非常有效。CX483井现场试验表明，采用纤维增强加砂压裂工艺，排液速度明显加快，排液时间显著缩短，见气时间显著提前，达到了“能快速、高效排液，避免支撑剂回流返吐”的应用效果。这项工艺的成功应用，为进一步降低川西低渗致密气藏压裂液的滞留伤害和预防因地面管线的冲蚀破坏而造成的安全生产隐患提供了可靠的技术保证，具有良好的推广应用前景。

FIELD APPLICATION OF FRACTURING TECHNIQUE WITH FIBER ENHANCED PROPPANT TO RAPIDLY FLOW BACK 1)

Backflow of proppants happens often during the production test and the early stage of gas exploitation after fracturing in Xinchang Gas Field of West Sichuan, which makes negative effects on the production test of fractured wells and the normal gas transmission. Therefore, the experiments of proppant stability under the different closure pressures, the different viscosities of fracturing fluid, and different fiber concentrations are conducted. The results show the critical flow rate of sand producing increases above 10 times and the stability is improved obviously for the bed filled by proppants with fibers, which prevents proppant backflow effectively. The field test of Well CX483 shows it makes the velocity of flowing back increasing obviously, the period of flowing back shortening largely, and the time of gas producing going ahead greatly to use the sand fracturing technique with fiber enhanced proppant, which reaches the results of “rapid and efficient flowing back, preventing backflow of proppants”. With success application of the technique, the reliable technical guarantee is provided to decrease the damage of tight gas reservoirs with low permeability in West Sichuan caused by staying of fracturing fluid, and prevent the potential safe accidents of surface pipelines damage caused by sand washout. The technique has good expanding and applying prospect.