低浓度压裂液体系在长庆致密油藏的研究与应用

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

卢拥军 杨晓刚 王春鹏 赵文 管保山 刘萍

LU Yongjun YANG Xiaogang WANG Chunpeng ZHAO Wen GUAN Baoshan LIU Ping

中国石油勘探开发研究院廊坊分院，河北廊坊　065007 中国石油油气藏改造重点实验室，河北廊坊　065007 中国石油长庆油田分公司，陕西西安　710018

Research Institute of Petroleum Exploration and Development, Langfang 065007, China Key Laboratory of Reservoir Stimulation, CNPC, Langfang 065007, China Changqing Oil.eld Company, PetroChina, Xi’an 710018, China

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。

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.