测井评价煤层气储层的方法探讨

根据煤层气储层实验室分析确定的体积模型（碳、灰分、挥发分、水分）,以测井曲线予以评价。其中以自然伽马测井确定湿灰分,该方法的前提条件是湿分主要是泥质且泥质不具放射性元素;以密度测井与人工伽马测井确定含碳量,并对密度测井作湿分校正;以灰分校正后的密度测井确定饱和水孔隙度;含气量的估算以声波测井和密度测井组成的复合参数ΔT/dDEN来确定,或以视电阻率曲线确定含气量。以某地区2个钻孔为例,讨论了煤层深度、压力等与水分、灰分、含气饱和度、含气量等参数的关系,认为含气量与深度成正比关系。

Probe into CBM Reservoir Evaluation through Well Logging

Based on CBM reservoir volume model （carbon, ash, volatile matter and moisture） defined by laboratory analysis, and then evaluated by logging traces. Of which, wet basis ash content is defined by gamma-ray log, and the precondition is the ash mainly argillaceous and contains no radioelement; carbon is defined by density log and artificial gamma log, and moisture calibration for density log; saturated porosity is defined by density log after ash calibration; gas content is defined by acoustic log and density log compound parameter AT/dDEN, or by apparent resistivity curves. To take 2 boreholes in an area as example, discussed relations between parameters of coal seam depth, pressure and moisture, ash, gas saturation, gas content, considered that the gas content and coal seam depth is directly proportional.