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近年来，煤层气勘探开发受到各方面的高度重视。针对煤田勘探主要采用传统钻井取心法进行瓦斯分析所带来不能满足多方需要的实际,结合石油录井技术，阐述应用岩性组合特征规律、标志层及钻时曲线、气测全烃曲线的对比分析预测煤岩取心位置， 以及利用钻时、dcs指数、气测异常等录井参数卡准煤层位置等技术方法。在此基础上，应用国外通过煤屑、煤心解吸试验研究成果，建立乙炔和甲烷的电压值间的函数关系，从而计算出煤层释放速率，进而得到煤岩含气量；利用气体参照法和钻井液热真空蒸馏法来计算煤层气含量，预测煤层的产能和估算储量。文章还论述了现场钻遇煤岩的基本特征和现场判断气层厚度的方法。

LOGGING TECHNIQUES IN COALBED METHANE EXPLORATION

In recent years，much attention has been paid by all circles to coalbed methane exploration and development.In consideration of that the gas analysis by use of drill coring method in conventional coal field exploration couldn′t satisfy many sided needs and in combination with petroleum logging techniques，it is pointed out in the paper that the coal rock coring interval can be predicted by applying lithological association law and through contrasting and analyzing the guiding bed，drilling time log and total hydrocarbon gas log，and the coalbed horizon may be exactly determined by use of these logging parameters as drilling time，dcs index and gas logging anomaly.On the basis of these technigues and methods，the functional relation between the voltage values of ethine and methane is set up by applying the foreign research results of desorption tests of coal fragments and coal cores，then the release rate of coalbed methane may be calculated，and then the methane content in coal rock can be obtained.The gas reference method and drilling fluid thermal vacuum distillation method may be used for calculating coalbed methane content，predicting methane deliverability and estimating its reserves in coalbed.The basic characteristics of drilling to coal rocks and the methods of identifying methane bearing formation thickness on the spot are introduced in the paper also.