CO_(2)干法压裂用支化硅氧烷及含氟聚合物类增稠剂研究现状与应用进展

Research status and application progress of branched siloxane and fluorinecontaining polymer thickeners for dry fracturing of carbon dioxide

近年来,CO_(2)干法压裂技术作为一种新型无水压裂技术已成为致密油气藏开发的重要研究方向。经调研发现,CO_(2)干法压裂技术尚未成熟,主要是因液态或超临界CO_(2)黏度低而存在滤失量大、携砂性能差等问题,需要加入增稠剂来提高CO_(2)的黏度。针对硅氧烷类增稠剂需借助大量助溶剂、其他增稠剂而增稠效果不理想、温度压力适应性差等问题,从增稠机理和增稠特性两方面概述了目前支化硅氧烷类(不使用或少量使用助溶剂)及含氟类增稠剂CO_(2)压裂液增稠剂的研究进展,并在增稠特性部分综述了这两类增稠剂的结构特征和性能特点。其次,对国内相关液态CO_(2)和超临界CO_(2)干法压裂技术现场应用进行综述。最后,分别从增稠机理、增稠性能和现场应用方面对干法压裂CO_(2)增稠剂及其压裂液体系未来的研究方向进行了展望。

CO_(2)dry fracturing technology,as a new waterless fracturing technique,has become an important research direction in tight oil and gas development in recent years.However,based on literature research,it is found that CO_(2)dry fracturing technology is not yet mature,mainly due to the low viscosity of liquid carbon dioxide or supercritical CO_(2),which leads to significant fluid loss and poor proppant carrying capacity.It requires thickening agents to significantly increase the viscosity of CO_(2).Considering the limitations of silicone-based thickeners that require a large amount of co-solvent and other thickeners with unsatisfactory thickening effects,as well as poor temperature and pressure adaptability,this paper provides an overview of the research progress on thickeners for CO_(2)fracturing fluids,focusing on branched silicone-based thickeners(with little or no co-solvent)and fluorinated thickeners from the perspectives of thickening mechanisms and thickening characteristics.In the thickening characteristics section,the structural and performance characteristics of these two types of thickeners are summarized.Additionally,the paper reviews the application of liquid CO_(2)and supercritical CO_(2)dry fracturing technology in China.Finally,the future research directions for CO_(2)thickeners and fracturing fluid systems in dry fracturing,including thickening mechanisms,thickening performance,and field applications,are discussed.