有水气藏特性及开采对策浅议

CHARACTERISTICS AND PRODUCTION POLICY OF GAS RESERVOIRS WITH WATER

有水气藏动态特征具有特殊性,其气水分布模式多样,同一水动力系统可能存在多个含气圈闭,正确认识气藏地质背景和水体驱动能量非常重要。气藏出水井可能出现在气藏任何位置,对于裂缝发育、构造平缓和高含水等气藏,更是如此。不同类型有水气藏,出水特征不同。产水气井动态特征可归纳为孔隙水产出、异层水产出和边水产出特征。地层水一旦获得必需的驱动力,比天然气更容易通过多孔介质,根本原因是水分子和天然气分子的物理特性不同,在一定驱动力下,水比烃类流体更具"通过性"。有水气藏在开采过程中发生水侵危害是必然的,合理布井、合理工作制度有利于延长气藏无水采气期和自喷生产时间。排水采气应该是降低地层水危害,提高开采效果的首选措施。有水气藏开采对策直接影响开采效果,开采对策应兼顾近期生产目标和远期开采效果,以提高气藏采收率为终极目标。

For gas reservoirs with water,not only the dynamic characteristics are very special,but also the gas-water distribution pattern is various.In the same hydrodynamic system,there may be several gas-bearing traps.Therefore,it's very important to understand correctly both geologic setting and waterbody drive energy.Water-producing wells may appear anywhere in the reservoir,especially for ones featured by developed fracture,gently structure and high water-cut.Different gas reservoirs with water have different water-producing characteristics.The dynamic characteristics can be concluded as pore water producing,producing water of other layers and edge water producing.Formation water can pass through porous media more easily than gas just because of the difference in physical properties of water and gas molecules.Under a certain driving pressure differential,the 'pass ability' of water is better than that of hydrocarbon.Water invasion occurring during production of gas reservoirs with water is inevitable.So suitable well pattern and working system are beneficial to increasing water-free gas production and extending flowing production period.Production policy has a direct effect on production and must give consideration to both short-term goal and long-term effect in order to enhance a final recovery.