| 摘要: |
| 目的 结合致密气藏“多尺度高密度”开发工艺要求,运用“中低分子量 + 增强链刚性 + 超分子聚集 + 抗盐单体”的设计思路,采用可控自由基聚合的方法,将缺电性的疏水链的刚性骨架功能单体与强极性的磺酸型抗盐功能单体可控地引入到分子链中,并结合复合悬浮技术研制一体化变黏抗盐降阻剂。方法 对一体化变黏抗盐降阻剂进行综合性能评价,考察了降阻剂的溶解性能、增黏携砂性能、抗盐耐温性能以及降阻性能。结果 在清水中,一体化变黏抗盐降阻剂的加量为0.03%(w)时降阻率可达81%,在超过20 000 mg/L矿化度的盐水中,黏度保持率为91%,降阻率保持在75%以上；通过调整降阻剂加量可实现体系在3.4～60.0 mPa·s的黏度范围内实时可调可变；与同类型常规乳液型降阻剂相比,静态悬砂能力大幅度提高,并能够满足150 ℃以上的储层施工需求；利用一体化变黏滑溜水体系配合多尺度高密度缝压裂工艺,在川西致密气现场实施7井次,施工成功率100%,单井平均降阻率81%,加砂强度(3.86 t/m)是前期常规一体化滑溜水改造工艺的7.7倍,现场应用效果显著。结论 研制的一体化变黏抗盐降阻剂性能优异,能够满足现场对滑溜水压裂液降阻携砂、耐温抗盐的综合需求,现场试验表明具有良好的应用前景。 |
| 关键词: 致密气 一剂多能 可变黏压裂液 强携砂 现场应用 |
| DOI：10.3969/j.issn.1007-3426.2022.05.012 |
| 分类号: |
| 基金项目:四川省科技成果转移转化示范项目“页岩气压裂用一体化变黏抗盐滑溜水关键技术研究及产业化”(2020ZHCG0054) |
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| Development and application of an integrated variable viscosity and anti-salt drag reducing agent |
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Guo Jianchun1, Ren Shan2, Tang Chaojun2, Zou Cunhu3, Ma Yingxian1,3, Diao Su2
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1. State Key Laboratory of oil and gas reservoir geology and Development Engineering ,Southwest Petroleum University, Chengdu, Sichuan, China;2. Chengdu LEPS Technology Co., Ltd., Chengdu, Sichuan, China;3. School of petroleum and natural gas engineering, Southwest Petroleum University, Chengdu, Sichuan, China
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| Abstract: |
| Objective Combining with the development process requirements of "multi-scale and high-density" for tight gas reservoirs, and based on the design idea of "medium and low molecular weight + enhanced chain rigidity + supramolecular aggregation + salt resistant monomer" and the method of controllable free radical polymerization is adopted to introduce the rigid skeleton functional monomer of hydrophobic chain lacking electricity and the strong polar sulfonic acid salt resistant functional monomer into the molecular chain, and the integrated variable viscosity and anti-salt drag reducing agent is developed in combination with the composite suspension technology. Methods The comprehensive properties of the integrated variable viscosity and anti-salt drag reducing agent were studied by experimental methods. The solubility, viscosity increasing and sand carrying properties, salt and temperature resistance and resistance reducing properties of drag reducing agents were investigated. Results The resistance reduction rate of integrated variable viscosity with a dosage of 0.03 wt% and anti-salt drag reducing agent in clean water could reach 81%. In brine with salinity over 20 000 mg/L, the viscosity retention rate was 91%, and the resistance reduction rate remained above 75%. The viscosity of the system could be adjusted in real time from 3.4 mPa·s to 60 mPa·s by adjusting the amount of resistance drag reducing agent. Compared with the same type of conventional emulsion type drag reducer, the static sand suspension ability was greatly improved, and it could meet the construction requirements of reservoirs above 150 ℃. Using the integrated variable viscosity slick water system combined with multi-scale high-density fracture fracturing technology to implement 7 wells in the tight gas field in western Sichuan, the construction success rate was 100%, the average resistance reduction rate of single well was 81%, the sand adding intensity was 3.86 t/m, which was 7.7 times of the conventional integrated slick water in the early stage, and the effect of field application is remarkable. Conclusion sThe excellent performance of the integrated variable viscosity and anti-salt drag reducing agent could meet the comprehensive requirements of the field construction, and the field application proves that it has a good application prospect. |
| Key words: tight gas multiple functions of one agent variable viscosity fracturing fluid strong sand-carrying field application |
