新场须二气藏产水识别及动态特征研究

Water Production Identification and Dynamic Characteristics of Second Member in Xu Jiahe Formation

摘要: 新场须二气藏气井测试产能差异较大，气井生产存在不同规律的出水，部分气井长期气水同产、部分气井生已发生水侵后难以复产。通过分析水化学特征、产水气井动态特征、测井模型等方法，开展气井产水识别，总结出产水气井三种动态特征，即低产水型、持续上升型、冲高回落型，分析出气井产水的主要原因是一是不合理的工作制度加速边底水的锥进，二是地层压力下降，压力波及至周围水淹体，三是“5∙12”大地震导致位于大规模断裂系统附近的气井纵向上下部雷口坡组气层水侵入，气井水化学特征发生变化，但矿化度未发生变化，从而为有水气藏的开发提供借鉴。

Abstract: The test productivity of second member in Xu Jiahe formation for Xin Chang gas field is quite dif-ferent, and the gas wells have different regularities of water production. Some gas wells have long- term co-production of gas and water, and some gas wells are difficult to resume production after water invasion. By analyzing water chemical characteristics, dynamic characteristics of water-pro- ducing gas wells, logging models, the water production identification of gas wells was carried out, and three dynamic characteristics of water-producing gas wells were summarized, namely low water production type, continuous rising type, and rising and falling type. The main reasons for water production were as followed. First, the unreasonable working system accelerated the coning of edge and bottom water. Second, with the formation pressure dropped, the pressure spread to the surrounding flooded bodies. Third, the water intrusion of the Lei Koupo formation gas reservoir in the vertical lower parts of the nearby gas wells changed the chemical characteristics of the gas well water, but the salinity did not change, which provided a reference for the development of water-bearing gas reservoirs.