液态CO2干法加砂压裂增稠剂技术现状及展望

CO_2干法加砂压裂是低压、低渗透、强水敏等非常规储层高效开发的有效措施之一。系统分析了目前国内外液态CO_2干法加砂压裂技术中增稠剂现状,对现有增稠剂分子结构进行分析归类,指出了增稠剂存在的主要技术问题和开发的难点。通过对目前国内液态CO_2干法压裂技术现状和现场试验情况梳理发现:国内液态CO_2增稠剂技术滞后于现场应用,压裂液携砂效率低,影响了压裂施工效果;分析国内外液态CO_2增稠剂研究存在的问题,借鉴现有研究成果,依据CO_2分子结构特征和理化特性,构建能使液态CO_2高效增黏的新型增稠剂分子结构,合成高质量的液态CO_2增稠剂,是实现液态CO_2干法加砂压裂的技术关键。在现有技术条件下,建议将液态CO_2干法压裂技术与常规无水压裂技术结合,既发挥了液态CO_2干法压裂技术优势,又实现了高砂比对压裂施工技术要求,满足非常规储层压裂开发需要。

Research progress and prospective in liquid CO2 dry fracturing thickeners technology

Liquid CO₂ dry fracturing technology is one of the effective measures for the development of unconventional reservoirs such as low pressure, low permeability and strong water sensitivity. The status of thickener in liquid CO₂ dry fracturing technology at home and abroad is analyzed, and the molecular structure of the existing thickener is classified. The main problems existing in thickener technology and the difficulties in development are pointed out. The present situation of liquid CO₂ dry fracturing technology and the field test results show that liquid CO₂ thickener technology has not kept pace with the field application, so that liquid CO₂ dry fracturing technology can not achieve sand fracturing. The effects of the technology on the application of liquid CO₂ enrichment are discussed. Based on the existing problems of liquid CO₂ fracturing thickener at home and abroad, it is proposed to re-understand the molecular structure and physical and chemical characteristics of CO₂, instead of imitating the existing research results, to construct and synthesize new type thickener. At the present stage, it is suggested to combine the liquid CO₂ dry fracturing technology with the conventional anhydrous fracturing technology, to effectively utilize the advantages of the liquid CO₂ dry fracturing technology, to realize the fracturing construction high sand ratio technology requirements, and to meet the unconventional reservoir fracturing development needs.