开平—涧河地区煤层气勘探前景

ANALYSIS OF COALBED METHANE EXPLORATION PROSPECT IN KAIPING -JIANHE

开平—涧河地区石炭二叠系煤层以 9# 和 1 2 # 煤层分布最稳定 ,煤岩组分以镜质组为主 ,平均达 70 %以上。煤热演化成熟度 Ro值在 0 .85%～ 1 .2 6%之间 ,煤阶分布具有从北往南、向斜轴部向两翼降低的特点。煤层割理倾向稳定 ,不受构造线影响 ,大多未被充填。等温吸附实验表明 ,煤的兰氏体积和兰氏压力分别为 30 .0 5m3 /t,3.1 3MPa。煤微孔结构根据吸附等温线和孔径分布特征可分为 3类。煤层上覆地层有效厚度具有由北向南减薄特点 ,北部向斜两翼断层带附近水体交替活跃 ,矿化度低 ,南部水体不活跃 ,矿化度高。煤层瓦斯分化带下限为 60 0 m。煤层含气量 6～ 1 2m3 /t,估算煤层埋深在 60 0～ 1 50 0 m范围内煤层气资源量为 70 5× 1 0 8m3。

Permo Carboniferous 9 # and 12 # coal beds are distributed steadily in Kaiping Jianhe Area.The vitrinite of maceral is more than 70%.The coal maturation are changed,Ro is between 0.85% and 1.26%,the higher rank distributed in the northwest part of this area and become lower to the southeast.The cleats developed with similar dip,and most of them are unfilled by mineral matter. The sorption isotherm shows that the Langmuir sorption is 30 03 m 3/t, the Langmuir pressure is 3.13 MPa.The thickniess of overlying rock is becoming thinner form northto south.The underground water in the syncline banks near the faults is active and the degree of mineralization is lower than in the southeast.The coalbed methane reserve in depth between 600 meters and 1500 meters is 705×10 8m 3;the gas content is between 6 12 m 3/t.Chengtuo Xiaoying block may become coalbed methane experimentation aera.