湘中地区海相页岩气资源潜力评价方法及参数选取

Evaluation methods of shale gas resource potential and selection of parameters in Central Hunan,China

页岩气作为新兴的重要非常规天然气资源,常规的油气评价体系已不能准确地评价其资源潜力。该文旨在探索海相页岩气资源潜力评价方法体系。以湘中地区下石炭统大塘阶测水段海相页岩层系为例,重点阐述非常规页岩气资源潜力体积法评价所涉及的参数选取原则,通过离散型参数条件概率分析其期望值,逐个选取评价参数。获得了大塘阶测水段页岩层系在条件概率分别为5%、25%、50%、75%、95%时的面积、厚度、总孔隙度、游离含气饱和度、吸附含气量、有机碳含量等11个参数值。初步估算了大塘阶测水段页岩气资源潜力。

As a new emerging type of nature gas,shale gas resources can not be evaluated by the existing conventional hydrocarbon evaluation methods.This paper aims to explore the evaluation methods of the marine shale gas resource potential.Taking the shale in Lower Carboniferous Datang Stage for example,it mainly expounds the principle of key parameter selection involved by the unconventional shale gas resource potential volume method.The key parameters are selected one by one and analyzes the expected value through the discrete data conditional probability.The research obtains 11 key parameters of the shale in Datang Stage with the conditional probability of 5%,25%,50%,75%,95%.They are the area,thickness,total porosity,free-gas saturation,absorbed gas content,TOC,etc..The resource potentialities of the shale in Datang Stage is preliminary estimated.