Discussion on Distribution Law and Influencing Factors of Ion Concentration and Types of Formation Water in Central Anticline Zone of Xihu Sag

Six gas fields have been put into development in Central Anticline Zone. According to the development performance of gas fields and water analysis data, it is found that there are obvious regional differences in chloride ion concentration and water types in the produced water of each production well, resulting in obvious differences in production characteristics of production wells. The author tries to analyze the chemical characteristics and ion composition of the produced water of each gas well. Combined with the production history, burial depth, reservoir forming mechanism and tectonic movement of each gas well, the reasons for the change of water types are analyzed, and the factors influencing the distribution law of water types and water production characteristics are discussed. It provides important reference significance for the stable development of each oil and gas field in Central Anticline Zone and the formulation of reasonable development technology policies. It also provides reference for the preparation of development plans in similar gas fields and efficient development of gas fields.