地层水在天然气保存中的积极作用

Positive Effect of Formation Water on Conservation of Natural Gas

利用实验和实测数据,结合气藏实例分析,对地层水在天然气保存中的积极作用进行了论述:①孔隙水的存在改变了泥质岩孔隙结构,使其排替压力增加、扩散系数降低,从而提高其阻止天然气渗漏和扩散的能力;②大量地层水为天然气提供了良好的暂存空间,避免了早期生成天然气的大量逸失,提高了天然气成藏的有效性;③由于地层水的存在,天然气可以以溶解态、水合物等形式富集下来,形成非常规气藏。地层水的参与,扩展了天然气聚集成藏的有利空间,也拓宽了天然气的勘探领域。

Based on the experimental and measured data, the positive effect of formation water on conservation of natural gas is discussed. The ease study shows that first, the existence of pore water could change the pore structure of mud, increase its displacement pressure, decrease its diffusion coefficient, thus effectively prevent natural gas from leaking and diffusion out of reservoir; second, plentiful formation water provides good storage space for natural gas, and avoids escape of early generated gas, thus adding possibility of natural gas accumulation; third, the existence of formation water allows natural gas to be accumulated in forms of solution state and hydrate for shaping non-conventional gas pool. Therefore, formation water is favorable for extension of space of gas accumulation, hence enlarging the scope or area for natural gas exploration.