低浓度压裂液体系在长庆致密油藏的研究与应用

根据长庆致密油藏低孔、低渗、低可动流体饱和度的特点，研制了稠化剂浓度为 0.15%~0.2%的低浓度压裂液体系（LCG）。该体系具有良好的耐温耐剪切性能、流变性能和破乳性能，破胶快速彻底。岩心损害率为 25.1%，压裂液残渣含量仅为 156 mg/L，不足以往使用压裂液的三分之一，降低了压裂液残渣对裂缝导流能力的损害。现场应用 7口井，投产 3个月后的产量和比采油指数分别为对比井的 1.59倍和 1.93倍，为致密油藏高效改造提供了一条有效途径。

Research and application of low concentration fracturing fluid in Changqing tight reservoirs

According to the characteristics of low porosity,low permeability and low movable fluid saturation in Changqing tight reservoirs,a kind of low concentration fracturing fluid(LCG) was developed with concentration of 0.15%-0.20%.The fluid has strong temperature and shearing resistance,good rheological properties,high demulsification performance and quick and through gel breaking performance.The average damage rate of permeability was 25.1%.The residue content of LCG was only 156 mg/L,less than one-third of the previously used fracturing fluid.It had achieved good application results in Changqing Oilfield.After fracturing treatment,the three months’ average production index of 7 test wells was 1.59 times as high as the compared well of the same well group.And the specific productivity index of test wells was 1.93 times as high as the compared well of the same well group.Using this fracturing fluid is one of the highly effective ways to stimulate the tight reservoirs.