松辽盆地南部致密气藏低伤害大型压裂改造技术研究与试验

松辽盆地南部深层致密气藏具有岩性多变、低孔、特低渗、埋藏深、杨氏模量高、压力高、温度高等特点，压裂改造的主要难点是加砂规模小、施工砂液比低，且易发生早期脱砂现象，使压裂改造效果一直难以获得突破。为此，研究了一种新的低伤害大型压裂技术，力求实现低伤害、深穿透、高导流的目标。其要点包括压前储层精细评价、耐高温耐剪切的低伤害压裂液体系、小粒径为主的高强度组合粒径支撑剂、压裂多级优化设计、螺旋式及段塞式加砂程序设计、新型压裂施工配套技术等。?两年9井次现场试验，成功率由以往的50%提高到80%以上，最高加砂量达90 m3，打开了松南盆地南部深层致密气藏的勘探局面，为今后的经济有效开发提供了重要的技术支撑。

Study and field test of low damage & massive hydraulic fracturing techniques in tight gas reservoirs in the south of Songliao Basin

Deep tight gas reservoirs in the south of Songliao Basin feature in complicated lithology, low porosity, ultra-low permeability, ultra depth, high Yang’s modulus, high pressure and high temperature. The key difficulties encountered include small proppant volume, low proppant concentration and early screen-out so that it is very difficult to get a satisfied post-fracturing effect. So a low damage massive hydraulic fracturing technique is put forward in this paper with the key object being low damage, longer penetration, and high fracture conductivity. To sum up, the highlights include fine formation evaluation before hydraulic fracturing, low damage fracturing fluid which can withstand high temperature and high shear rate, combination of different diameter of high strength proppants with smaller one being the main body, multiple stage optimization of fracturing design, spiral or slugging mode of proppant pumping schedule, new corresponding measures etc. By conducting nine well tests in two years, the hydraulic fracturing success ratio and effective percentage has been improved a lot than ever before （from 50% to 80% above）, with the proppant volume and proppant concentration breaking through history records continuously （such the maximal proppant volume is 90 m3 compared with 30 m3 below in the past mostly）, which provides technical support for tight gas exploration and development in the south of Songliao Basin.