活跃地下水对煤层气藏的破坏及其物理模拟

DAMAGE OF ACTIVE GROUNDWATER TO COALBED METHANE RESERVOIRS AND ITS PHYSICAL SIMULATION

水文地质条件是影响煤层气富集成藏的重要因素之一,但是目前与之相关的研究却比较薄弱。为此,通过研究活跃的地下水不仅使煤层含气性降低,同时也导致煤层甲烷碳同位素值变轻的现象,应用FY-Ⅱ型煤层气成藏模拟系统,探讨了活跃的地下水对煤层气藏的破坏作用。结果显示,活跃的地下水会破坏煤层气富集成藏,对煤层气的保存不利,而地下水滞留区才是煤层气勘探的有利区域。

Research on hydrogeological conditions is relatively poor at present, though it is one of the critical factors influencing the accumulation of coalbed methane. Active groundwater can not only make the gas-bearing properties of coal seam poorer, but also lower the carbon isotope of coalbed methane. The damage of active groundwater to coalbed methane reservoirs is studied by using the simulation system type FY-Ⅱof coalbed methane reservoir. The simulation results show that active groundwater has negative effects on the accumulation of coalbed methane and is unfavorable for the preservation of coalbed methane, while stagnant zone of groundwater is favorable for the exploration of coalbed methane reservoirs.