纳米材料改善压裂液性能及驱油机理研究

Study on Mechanism of the Fracturing Fluid Performance Improvement and Oil Displacement Using Nanomaterials

刘建坤 蒋廷学 黄静 吴春方 贾文峰 陈晨

LIU Jiankun JIANG Tingxue HUANG Jing WU Chunfan JIA Wenfeng CHEN Chen

页岩油气富集机理与有效开发国家重点实验室，北京 102206 中国石化石油工程技术研究院，北京 102206

State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing, 102206, China Sinopec Research Institute of Petroleum Engineering, Beijing, 102206, China

为给研发功能性压裂液提供理论依据，在纳米尺度（50 nm）对SiO2进行C8和季铵盐（QAS）修饰，合成了疏水纳米材料SiO2-C8和疏水带电纳米材料SiO2-QAS，评价了SRFP型聚合物清洁压裂液分别加入SiO2，SiO2-C8及SiO2-QAS等3种纳米材料后的配伍性、稳定性及综合性能；利用量化模拟手段，建立了纳米材料在砂岩表面的吸附结构模型及吸附动力学模型，分析了纳米材料在砂岩表面的吸附及油水分离特征。试验及模拟结果表明：SiO2，SiO2-C8及SiO2-QAS等3种纳米材料在压裂液中具有较好的分散稳定性，可有效降低表界面张力，表现出良好的耐温、耐剪切性能；SiO2-C8和SiO2-QAS加入压裂液后有利于砂岩表面油分子被置换出，促进油水分离；SiO2-C8和SiO2–QAS加入压裂液后可有效改善压裂液性能，提高驱油效果，降低压裂液波及范围内的含油饱和度。研究结果可为功能性压裂液发展和研制提供理论依据，为优化致密油、页岩油压裂方案和优选压裂液提供参考。

To provide a theoretical basis for the development of functional fracturing fluids, SiO2 was modified with C8 and quaternary ammonium salt (QAS) on nanoscale (50 nm). The hydrophobic nanomaterial SiO2-C8 and hydrophobic charged nanomaterial SiO2-QAS were synthesized. The compatibility, stability, and comprehensive performance of the SRFP polymer clean fracturing fluid systems were evaluated as nanomaterials SiO2, SiO2-C8, and SiO2-QAS were added. Quantitative simulation methods were employed to build the adsorption structure models and adsorption kinetics models of the nanomaterials on the sandstone surface. The adsorption and oil-water separation characteristics of nanomaterials on sandstone surfaces were analyzed. The experimental and simulation results show that the three nanomaterials, SiO2, SiO2-C8, and SiO2-QAS, display favorable dispersion stability in fracturing fluids. They can effectively reduce the surface and interfacial tension and demonstrate good temperature and shear resistance. SiO2-C8 and SiO2-QAS nanomaterials are beneficial to the replacement of oil molecules on the sandstone surface and the oil-water separation when they are added into fracturing fluids. The addition of nanomaterials SiO2-C8 and SiO2-QAS can also effectively improve the performance of fracturing fluids, enhance oil displacement, and reduce oil saturation within the spread range of fracturing fluids. The research results can provide a theoretical basis for the development of functional fracturing fluids and a reference for fracturing design optimization and fracturing fluid selection for tight oil and shale oil.

国家自然科学基金项目“页岩油气高效开发基础理论”（编号：51490653）、中国石化科技攻关项目“鄂南致密油藏两级裂缝高导流复合压裂技术研究”（编号：P17005-5）联合资助

https://doi.org/10.11911/syztjs.2021118