超临界CO_2增黏机制研究进展及展望

研制临界CO2增黏剂,突破超临界CO2压裂技术,是实现页岩气高效开发的一条有效途径。通过文献调研,对超临界CO2增黏剂研制现状、增黏剂在超临界CO2中的溶解机制、增黏剂-CO2相互作用机制、增黏剂的作用机制及其分子设计方法、超临界CO2增黏面临的问题等方面进行分析,总结超临界CO2增黏机制的研究动向。研究认为:具备两亲特性的新型低聚表面活性剂或酯类化合物是值得研究的备选增黏剂;应开发新型低密度支撑剂,与增黏剂共同用于超临界CO2压裂;研究含氟化合物在超临界CO2中的溶解机制及其分子间相互作用规律,有助于开发不含氟超临界CO2增黏剂;选择合适的分子模拟计算方法可以从微观上为超临界CO2增黏剂的分子设计提供理论指导。

Research progress and prospectives of supercritical CO2 thickening technology

CO₂ can be used as a fracturing fluid for shale gas development, in which effective thickening agents are needed to increase the viscosity of the supercritical CO₂ fluid. The state of the art for the techniques used for CO₂ thickening was reviewed and assessed, including various mechanisms involved in CO₂ thickening for its application in oil and gas industry and different thickening agents investigated in terms of their dissolution and intermolecular interactions with CO₂. The working mechanisms and molecular design methods used for selecting and design CO₂ thickening agents and the main difficulties involved were analyzed and summarized. It is proposed that novel amphiphilic oligomer surfactants and ester compounds are prospective thickening agents worthy of studying, and low density proppants can be used in supercritical CO₂ fracturing along with the thickening agents. The research progresses on the dissolution mechanism of fluorinated compounds in CO₂ and the solute-solvent interactions are useful for the development of non-fluorinated thickening agents. The molecular simulation method can provide theoretical guidance for molecular design of low cost and effective thickening agents.