焦作煤田煤层气储气层特征及含气性

THE CHRACTERITIC AND ITS GAS-BEARING PROPERTIES OF GAS STORAGE LAYER IN COALBED GAS IN JIAOZUO COALFIELD

焦作煤田的二1煤层厚度稳定,结构简单,且煤层气资源丰富。煤层的孔裂隙、吸附性、含气性、渗透性、储层压力、含气饱和度、储层温度等煤储层特征是煤层气选区评价和勘探开发决策的重要依据之一。通过对煤储层特征和分布规律深入的分析和研究认为:①焦作煤田二1煤层的纳米级孔隙发育,煤层吸附能力较强,且随着埋深的增加,吸附能力增大;②该煤层多数处于低压状态,但随着埋深的增加,储层压力和压力梯度有增大的趋势。③煤层气含量和含气饱和度随埋深的变化呈现相近的变化规律,含气量越大,甲烷(CH4)含量越大,甲烷(CH4)含量由浅至深有增大的趋势。④根据我国渗透率划分标准,该煤层原始煤储层的渗透率多数属于中高渗透率煤层,局部地段属于低渗透煤层。

There is abundant coal gas in the No.2 thickness of coal seamsetting and sipliy structure, one of the important foundation for decisison making of evluation and exploititon of electorate area is the coal storatge chracters（fissure,adsorption,penetrability , coal storage seam tension,gas saturation,temperature of coal storage seam）. Research and study on the coal storage seam and its distribution regulation, ①the developing of fissure in a level of nanometer and with the strong absorb ability ,along with the crease of the deepth of the embedding ,the stronger of the absord ability; ②this coal seam mostly in a low pressure, but with the increase of the imbedding deepth ,the storage seam pressure and its pressure gradient trend to incresent ; ③the changing of the content of coalbed gas and gas staturation with the imbedding deepth have the close variation rule, the higher the gas content. The higher the content of the CH4, and the content of the CH4 trend to increasing fi＇om the superficial part to deep part, ④accroading to the criteria of permeability, the permeability of the original coal storage seam of this coal bed mostly belongs to the high permeability coal bed ,part of it belongs to the low permeability coat bed.