致密砂岩气藏成藏过程的物理模拟实验

Physical Simulation Experiment of Gas Charging in Tight Sandstone

致密砂岩气藏具有广阔的资源前景,可以有效地弥补常规天然气资源的不足。但其成藏过程和气水分布关系的研究是一个相对不足而又非常重要的领域,它的完善直接关系到勘探的成败。本文正是针对这一研究领域,采用物理模拟实验方法,通过实际资料的调研,建立了二维的实验模型,对致密砂岩气藏的成藏过程和气水分布关系进行了模拟。实验结果表明,致密砂岩气藏的成藏过程可以分为三个阶段,分别为:充注前期(能量积累阶段)、充注期(幕式充注成藏阶段)、充注后期(气藏保存阶段)。其中,幕式充注成藏阶段是致密气藏成藏的关键时期。而导致气水分布关系复杂的原因在于储层的非均质性。

Tight sandstone gas reservoirs have a great potential of resource, which can make up the conventional natural gas. Although the accumulation process and gas--water distribution of tight sandstone gas is so important to the success of gas exploration, the study on them are insufficient. In order to cope with the above scientific challenges, after adequately reviewing and comprehending previous research findings, a serial of 2D physical experiments have been done to simulate the accumulation process and gas--water distribution of tight sandstone gas. The result of the experiment showed that the accumulation process of tight sandstone gas can be divided into three stages; they are the precharging stage of energy accumulation, the charging stage of gas episode-charging and the post-charging stage of natural gas conservation. The stage of gas episode-charging is the key for tight sandstone gas reservoirs. And the complexity of gas--water distribution is contributed to the heterogeneous reservoir.