宜昌地区页岩气压裂液体系应用研究

Study on application of shale gas fracturing fluid system in Yichang Area

分析了宜昌地区页岩气储层特征及对压裂液低温低伤害与“变黏”的需求,通过室内试验与工程实践研发了适用于宜昌地区页岩的FLICK低温低伤害滑溜水、LOMO低温低伤害胶液体系。针对高碳酸盐岩含量页岩储层研发了RATER减阻酸并探索了多级交替注入减阻酸改造工艺。介绍了FLICK滑溜水低温降解性能,LOMO胶液超强悬砂性能,RATER减阻酸配方与性能。现场应用结果表明:低温低伤害压裂液体系减阻率大于75%,返排液黏度小于2 mPa·s,分子量小于1万,适用于常压低温页岩气储层;多级交替注入减阻酸利于复杂缝网的形成且有利于改善储层基质渗透率。

The characteristics of shale gas reservoir in Yichang area and the demand for low-temperature,low-damage and"viscosification"of fracturing fluid are analyzed.The FLICK low-temperature and low-damage slickwater and LOMO low-temperature and low-damage gel suitable for shale gas in Yichang area are developed through laboratory experiment and engineering practice.RATER reducing acid is developed for shale reservoir with high carbonate content,and a reservoir reconstruction method of multistage alternating injection of reducing acid is explored.The degradation performance of FLICK slickwater at low temperature,the super suspended sand performance of LOMO gel,and the formula and performance of RATER reducing acid are introduced.The results show that the drag reduction rate of low-temperature and low-damage fracturing fluid system is more than 75%,the viscosity of flow back fluid is less than 2 mPa·s,and the molecular weight is less than 10000,which is suitable for normal pressure low temperature shale gas reservoir.Multistage alternating injection of reducing acid is beneficial to the formation of complex fracture networks and the improvement of reservoir matrix permeability.