湘中下石炭统测水组煤层气储层特性研究

Characteristic Study of Lower Carboniferous Ceshui Formation CBM Reservoir in Central Hunan

从煤岩煤质、含气性、吸附特征、裂隙发育及渗透性等方面对湘中下石炭统测水组煤层气储层(煤储层)特性进行论述。研究表明煤储层为明显的富镜质组煤,随温度、压力的增加吸附量增大。区内煤层最大含气量为41.91m3/t,以新化芦毛江至金竹山一带为中心,包括芦毛江、冷水江、渣渡、金竹山等矿区,高富集区基本呈东西向展布。但受煤阶的影响,煤层内生裂隙发育程度明显低于龙潭组煤层,同时由于煤层煤体结构连通性差以及多起构造运动形成细小的煤粉常充填于构造裂隙中,降低了煤层的渗透性。针对上述煤储层特点,指出加强对具有上封下开裂隙系统以及原生结构煤和碎裂煤整层发育地区的煤层气勘探尤为重要。

From aspects of coal lithology,quality,gas potential,adsorption characters,fissure development and permeability discussed CBM reservoir（coal reservoir） characteristics in central Hunan Lower Carboniferous Ceshui Formation.The study has shown the reservoir coal is rich in vitrinite and adsorption quantity increasing along with increasing of temperature and pressure.Coal seam maximum gas content is 41.91m3/t,centered in Lumaojiang to Jinzhushan district,Xinhua,covering Lumaojiang,Lengshuijiang,Zhadu and Jinzhushan mine areas,high enrichment zone basically east to west extended.As impacted by coal ranks,endokinetic fissures in the Ceshui Formation coals is obviously less than in the Longtan Formation coals.Meanwhile,since poorer coal body structural connectivity and multiphase tectonic movements formed coal fines often filled in tectonic fissures and lowered down coal seam permeability.In allusion to above coal reservoir characteristics,pointed out to strengthen CBM exploration in top closing bottom opening fissure system and undeformed,deformed coals full seam developed areas is especially important.