黔西都格井田煤层气储层特征及可采性

为预测评价黔西都格井田煤层气资源的可采潜力，推进黔西地区薄至中厚煤层群发育条件下的煤层气勘探开发工作，基于在该井田内实施的煤层气井所获得的地质资料，分析了可采煤层和顶底板发育条件、储层压力、含气性和孔渗性等重要储层地质特征，利用等温吸附曲线、相似地区储层类比和实际排采结果拟合等方法预测了煤层气可采性。结果表明:都格井田可采煤层含气量为3.94~29.95 m3/t，平均12.48 m3/t，含气饱和度平均为60%，煤储层以常压为主，含气饱和度较高，并有含气量高、孔渗性好的特点。通过等温吸附曲线法、类比法、排采试验数据拟合等3种不同方法预测都格井田可采系数分别为:0.49~0.68，0.40~0.53和0.41，综合评价可采系数为0.41~0.68，说明了井田具有较好的煤层气开发条件和可采性。

Reservoir characteristics and recoverability of CBM resource in Duge coalfield of Western Guizhou

To evaluate the CBM recoverable potential of Duge coalfield in western Guizhou province and promote the development of CBM in multiple thin coal seams,the formation condition of coal seams and adjacent roof and floor,the reservoir pressure,gas content,porosity and permeability are discussed based on the geological data from CBM wells in Duge coalfield.The recoverable coefficient is predicted using isothermal adsorption curve,similar coal seams analogy and production data fitting.The results show that the gas content of Duge coalfield is 3.94-29.95 m3/t,12.48 m3/t in average,and the average gas saturation is 60%.The pressure of most coal seams is normal.The coal seams are of high gas content and gas saturation,and large porosity and permeability.The recoverable coefficients predicted by isothermal adsorption curve,similar coal seams analogy and production data fitting are 0.49-0.68,0.40-0.53 and 0.41,which is evaluated as 0.41-0.68 comprehensively.High CBM recoverable coefficient indicates good geological conditions and development potential of the coal seams in Duge coalfield.