储气库用大尺寸可溶封隔器研制及试验

Development and Test of Large-Sized Soluble Packer Used in Gas Storage

在储气库不压井作业中,常规封隔器存在综合成本高、尺寸受限、溶解效果差等问题。为此,研制出一种适用于外径177.8 mm套管的大尺寸可溶封隔器。根据相关技术要求和生产需求,对该封隔器关键部件进行力学计算校核,对主体结构参数进行优化设计,在模拟地层液、KCl溶液以及柠檬酸溶液中,对配比出的镁铝合金进行室内溶解试验,并对主体结构力学性能进行仿真分析。分析结果表明:该封隔器可满足在3~15 d内储气库封隔要求,并且其溶解速率高效可控;封隔器材料溶解速率约为10~35 mg/(cm^(2)·h),溶解速度较为平稳且可控;加工样机通过室内承压试验,此封隔器可在90℃下承压40 MPa,满足现场作业要求。所得结论可为储气库大尺寸暂堵技术研究及现场作业施工提供技术参考。

In the snubbing operation of gas storage,conventional packers have problems such as high composite cost,limited size and poor dissolution effect.A large-sized soluble packer suitable for 177.8 mm O.D.casing was developed.According to relevant technical requirements and production demands,mechanical calculations and verifications were carried out on the key part of the packer,and optimization design was carried out for the main structural parameters.Moreover,laboratory dissolution tests were conducted on the prepared magnalium in simulated formation fluid,KCl solution and citric acid solution,and simulation analysis was conducted on the mechanical properties of the main structure.The analysis results show that the packer can meet the packoff requirements of gas storage within 3~15 days,and its dissolution rate is efficient and controllable.The dissolution rate of the packer material is about 10~35 mg/(cm^(2)·h),and is relatively smooth and controllable.The processed prototype has passed laboratory bearing test,and the packer can withstand a pressure of 40 MPa at 90℃,meeting the requirements of field operations.The conclusions provide technical reference for the research and field operation of large-sized temporary blocking technology in gas storage.